mongo

package
v1.2.1 Latest Latest
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 Go to latest Published: Jan 8, 2020 License: Apache-2.0 Imports: 34 Imported by: 0

Documentation

Overview

Package mongo provides a MongoDB Driver API for Go.

Basic usage of the driver starts with creating a Client from a connection string. To do so, call the NewClient and Connect functions: 

client, err := NewClient(options.Client().ApplyURI("mongodb://foo:bar@localhost:27017"))
if err != nil { return err }
ctx, cancel := context.WithTimeout(context.Background(), 20*time.Second)
defer cancel()
err = client.Connect(ctx)
if err != nil { return err }

This will create a new client and start monitoring the MongoDB server on localhost. The Database and Collection types can be used to access the database: 

collection := client.Database("baz").Collection("qux")

A Collection can be used to query the database or insert documents: 

res, err := collection.InsertOne(context.Background(), bson.M{"hello": "world"})
if err != nil { return err }
id := res.InsertedID

Several methods return a cursor, which can be used like this: 

cur, err := collection.Find(context.Background(), bson.D{})
if err != nil { log.Fatal(err) }
defer cur.Close(context.Background())
for cur.Next(context.Background()) {
  // To decode into a struct, use cursor.Decode()
  result := struct{
    Foo string
    Bar int32
  }{}
  err := cur.Decode(&result)
  if err != nil { log.Fatal(err) }
  // do something with result...

  // To get the raw bson bytes use cursor.Current
  raw := cur.Current
  // do something with raw...
}
if err := cur.Err(); err != nil {
  return err
}

Methods that only return a single document will return a *SingleResult, which works like a *sql.Row: 

result := struct{
  Foo string
  Bar int32
}{}
filter := bson.D{{"hello", "world"}}
err := collection.FindOne(context.Background(), filter).Decode(&result)
if err != nil { return err }
// do something with result...

All Client, Collection, and Database methods that take parameters of type interface{} will return ErrNilDocument if nil is passed in for an interface{}.

Additional examples can be found under the examples directory in the driver's repository and on the MongoDB website.

Potential DNS Issues

Building with Go 1.11+ and using connection strings with the "mongodb+srv"[1] scheme is incompatible with some DNS servers in the wild due to the change introduced in https://github.com/golang/go/issues/10622. If you receive an error with the message "cannot unmarshal DNS message" while running an operation, we suggest you use a different DNS server.

Client Side Encryption

Client-side encryption is a new feature in MongoDB 4.2 that allows specific data fields to be encrypted. Using this feature requires specifying the "cse" build tag during compilation.

Note: Auto encryption is an enterprise-only feature.

The libmongocrypt C library is required when using client-side encryption. To install libmongocrypt, follow the instructions for your operating system:

1. Linux: follow the instructions listed at https://github.com/mongodb/libmongocrypt#installing-libmongocrypt-from-distribution-packages to install the correct deb/rpm package.

2. Mac: Follow the instructions listed at https://github.com/mongodb/libmongocrypt#installing-libmongocrypt-on-macos to install packages via brew and compile the libmongocrypt source code.

  1. Windows: mkdir -p c:/libmongocrypt/bin mkdir -p c:/libmongocrypt/include

    // Run the curl command in an empty directory as it will create new directories when unpacked. curl https://s3.amazonaws.com/mciuploads/libmongocrypt/windows/latest_release/libmongocrypt.tar.gz --output libmongocrypt.tar.gz tar -xvzf libmongocrypt.tar.gz

    cp ./bin/mongocrypt.dll c:/libmongocrypt/bin cp ./include/mongocrypt/*.h c:/libmongocrypt/include export PATH=$PATH:/cygdrive/c/libmongocrypt/bin

libmongocrypt communicates with the mongocryptd process for automatic encryption. This process can be started manually or auto-spawned by the driver itself. To enable auto-spawning, ensure the process binary is on the PATH. To start it manually, use AutoEncryptionOptions: 

aeo := options.AutoEncryption()
mongocryptdOpts := map[string]interface{}{
    "mongocryptdBypassSpawn": true,
}
aeo.SetExtraOptions(mongocryptdOpts)

To specify a process URI for mongocryptd, the "mongocryptdURI" option can be passed in the ExtraOptions map as well. See the ClientSideEncryption and ClientSideEncryptionCreateKey examples below for code samples about using this feature.

[1] See https://docs.mongodb.com/manual/reference/connection-string/#dns-seedlist-connection-format

Example (ClientSideEncryption) 
// This would have to be the same master key that was used to create the encryption key
localKey := make([]byte, 96)
if _, err := rand.Read(localKey); err != nil {
	log.Fatal(err)
}
kmsProviders := map[string]map[string]interface{}{
	"local": {
		"key": localKey,
	},
}
keyVaultNamespace := "admin.datakeys"

uri := "mongodb://localhost:27017"
autoEncryptionOpts := options.AutoEncryption().
	SetKeyVaultNamespace(keyVaultNamespace).
	SetKmsProviders(kmsProviders)
clientOpts := options.Client().ApplyURI(uri).SetAutoEncryptionOptions(autoEncryptionOpts)
client, err := Connect(context.TODO(), clientOpts)
if err != nil {
	log.Fatalf("Connect error: %v", err)
}
defer func() {
	if err = client.Disconnect(context.TODO()); err != nil {
		log.Fatalf("Disconnect error: %v", err)
	}
}()

collection := client.Database("test").Collection("coll")
if err := collection.Drop(context.TODO()); err != nil {
	log.Fatalf("Collection.Drop error: %v", err)
}

if _, err = collection.InsertOne(context.TODO(), bson.D{{"encryptedField", "123456789"}}); err != nil {
	log.Fatalf("InsertOne error: %v", err)
}
res, err := collection.FindOne(context.TODO(), bson.D{}).DecodeBytes()
if err != nil {
	log.Fatalf("FindOne error: %v", err)
}
fmt.Println(res)

Output:
Example (ClientSideEncryptionCreateKey) 
keyVaultNamespace := "admin.datakeys"
uri := "mongodb://localhost:27017"
// kmsProviders would have to be populated with the correct KMS provider information before it's used
var kmsProviders map[string]map[string]interface{}

// Create Client and ClientEncryption
clientEncryptionOpts := options.ClientEncryption().
	SetKeyVaultNamespace(keyVaultNamespace).
	SetKmsProviders(kmsProviders)
keyVaultClient, err := Connect(context.TODO(), options.Client().ApplyURI(uri))
if err != nil {
	log.Fatalf("Connect error for keyVaultClient: %v", err)
}
clientEnc, err := NewClientEncryption(keyVaultClient, clientEncryptionOpts)
if err != nil {
	log.Fatalf("NewClientEncryption error: %v", err)
}
defer func() {
	// this will disconnect the keyVaultClient as well
	if err = clientEnc.Close(context.TODO()); err != nil {
		log.Fatalf("Close error: %v", err)
	}
}()

// Create a new data key and encode it as base64
dataKeyID, err := clientEnc.CreateDataKey(context.TODO(), "local")
if err != nil {
	log.Fatalf("CreateDataKey error: %v", err)
}
dataKeyBase64 := base64.StdEncoding.EncodeToString(dataKeyID.Data)

// Create a JSON schema using the new data key. This schema could also be written in a separate file and read in
// using I/O functions.
schema := `{
		"properties": {
			"encryptedField": {
				"encrypt": {
					"keyId": [{
						"$binary": {
							"base64": "%s",
							"subType": "04"
						}
					}],
					"bsonType": "string",
					"algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic"
				}
			}
		},
		"bsonType": "object"
	}`
schema = fmt.Sprintf(schema, dataKeyBase64)
var schemaDoc bson.Raw
if err = bson.UnmarshalExtJSON([]byte(schema), true, &schemaDoc); err != nil {
	log.Fatalf("UnmarshalExtJSON error: %v", err)
}

// Configure a Client with auto encryption using the new schema
dbName := "test"
collName := "coll"
schemaMap := map[string]interface{}{
	dbName + "." + collName: schemaDoc,
}
autoEncryptionOpts := options.AutoEncryption().
	SetKmsProviders(kmsProviders).
	SetKeyVaultNamespace(keyVaultNamespace).
	SetSchemaMap(schemaMap)
client, err := Connect(context.TODO(), options.Client().ApplyURI(uri).SetAutoEncryptionOptions(autoEncryptionOpts))
if err != nil {
	log.Fatalf("Connect error for encrypted client: %v", err)
}

// Use client for operations.

if err = client.Disconnect(context.TODO()); err != nil {
	log.Fatalf("Disconnect error: %v", err)
}

Output:

Index

Examples

Constants

This section is empty.

Variables

View Source 
var ErrClientDisconnected = errors.New("client is disconnected")

ErrClientDisconnected is returned when disconnected Client is used to run an operation.

View Source 
var ErrEmptySlice = errors.New("must provide at least one element in input slice")

ErrEmptySlice is returned when an empty slice is passed to a CRUD method that requires a non-empty slice.

View Source 
var ErrInvalidIndexValue = errors.New("invalid index value")

ErrInvalidIndexValue is returned if an index is created with a keys document that has a value that is not a number or string.

View Source 
var ErrMissingResumeToken = errors.New("cannot provide resume functionality when the resume token is missing")

ErrMissingResumeToken indicates that a change stream notification from the server did not contain a resume token.

View Source 
var ErrMultipleIndexDrop = errors.New("multiple indexes would be dropped")

ErrMultipleIndexDrop is returned if multiple indexes would be dropped from a call to IndexView.DropOne.

View Source 
var ErrNilCursor = errors.New("cursor is nil")

ErrNilCursor indicates that the underlying cursor for the change stream is nil.

View Source 
var ErrNilDocument = errors.New("document is nil")

ErrNilDocument is returned when a nil document is passed to a CRUD method.

View Source 
var ErrNoDocuments = errors.New("mongo: no documents in result")

ErrNoDocuments is returned by SingleResult methods when the operation that created the SingleResult did not return any documents.

View Source 
var ErrNonStringIndexName = errors.New("index name must be a string")

ErrNonStringIndexName is returned if an index is created with a name that is not a string.

View Source 
var ErrUnacknowledgedWrite = errors.New("unacknowledged write")

ErrUnacknowledgedWrite is returned by operations that have an unacknowledged write concern.

View Source 
var ErrWrongClient = errors.New("session was not created by this client")

ErrWrongClient is returned when a user attempts to pass in a session created by a different client than the method call is using.

Functions

func BatchCursorFromCursor 

func BatchCursorFromCursor(c *Cursor) *driver.BatchCursor

BatchCursorFromCursor returns a driver.BatchCursor for the given Cursor. If there is no underlying driver.BatchCursor, nil is returned. This method is deprecated and does not have any stability guarantees. It may be removed in the future.

func WithSession 

func WithSession(ctx context.Context, sess Session, fn func(SessionContext) error) error

WithSession creates a new SessionContext from the ctx and sess parameters and uses it to call the fn callback. The SessionContext must be used as the Context parameter for any operations in the fn callback that should be executed under the session.

If the ctx parameter already contains a Session, that Session will be replaced with the one provided.

Any error returned by the fn callback will be returned without any modifications.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"go.mongodb.org/mongo-driver/mongo/readconcern"
)

func main() {
	var client *mongo.Client // assume client is configured with write concern majority and read preference primary

	// Specify the DefaultReadConcern option so any transactions started through the session will have read concern
	// majority.
	// The DefaultReadPreference and DefaultWriteConcern options aren't specified so they will be inheritied from client
	// and be set to primary and majority, respectively.
	opts := options.Session().SetDefaultReadConcern(readconcern.Majority())
	sess, err := client.StartSession(opts)
	if err != nil {
		log.Fatal(err)
	}
	defer sess.EndSession(context.TODO())

	// Call WithSession to use the new Session to insert a document and find it.
	err = mongo.WithSession(context.TODO(), sess, func(sessCtx mongo.SessionContext) error {
		// Use sessCtx as the Context parameter for InsertOne and FindOne so both operations are run under the new
		// Session.

		coll := client.Database("db").Collection("coll")
		res, err := coll.InsertOne(sessCtx, bson.D{{"x", 1}})
		if err != nil {
			return err
		}

		var result bson.M
		if err = coll.FindOne(sessCtx, bson.D{{"_id", res.InsertedID}}).Decode(result); err != nil {
			return err
		}
		fmt.Println(result)
		return nil
	})
}

Output:

Types

type BSONAppender 

type BSONAppender interface {
	AppendBSON([]byte, interface{}) ([]byte, error)
}

BSONAppender is an interface implemented by types that can marshal a provided type into BSON bytes and append those bytes to the provided []byte. The AppendBSON can return a non-nil error and non-nil []byte. The AppendBSON method may also write incomplete BSON to the []byte.

type BSONAppenderFunc 

type BSONAppenderFunc func([]byte, interface{}) ([]byte, error)

BSONAppenderFunc is an adapter function that allows any function that satisfies the AppendBSON method signature to be used where a BSONAppender is used.

func (BSONAppenderFunc) AppendBSON 

func (baf BSONAppenderFunc) AppendBSON(dst []byte, val interface{}) ([]byte, error)

AppendBSON implements the BSONAppender interface

type BulkWriteError 

type BulkWriteError struct {
	WriteError            // The WriteError that occurred.
	Request    WriteModel // The WriteModel that caused this error.
}

BulkWriteError is an error that occurred during execution of one operation in a BulkWrite. This error type is only returned as part of a BulkWriteException.

func (BulkWriteError) Error 

func (bwe BulkWriteError) Error() string

Error implements the error interface.

type BulkWriteException 

type BulkWriteException struct {
	// The write concern error that occurred, or nil if there was none.
	WriteConcernError *WriteConcernError

	// The write errors that occurred during operation execution.
	WriteErrors []BulkWriteError
}

BulkWriteException is the error type returned by BulkWrite and InsertMany operations.

func (BulkWriteException) Error 

func (bwe BulkWriteException) Error() string

Error implements the error interface.

type BulkWriteResult 

type BulkWriteResult struct {
	// The number of documents inserted.
	InsertedCount int64

	// The number of documents matched by filters in update and replace operations.
	MatchedCount int64

	// The number of documents modified by update and replace operations.
	ModifiedCount int64

	// The number of documents deleted.
	DeletedCount int64

	// The number of documents upserted by update and replace operations.
	UpsertedCount int64

	// A map of operation index to the _id of each upserted document.
	UpsertedIDs map[int64]interface{}
}

BulkWriteResult is the result type returned by a BulkWrite operation.

type ChangeStream 

type ChangeStream struct {
	// Current is the BSON bytes of the current event. This property is only valid until the next call to Next or
	// TryNext. If continued access is required, a copy must be made.
	Current bson.Raw
	// contains filtered or unexported fields
}

ChangeStream is used to iterate over a stream of events. Each event can be decoded into a Go type via the Decode method or accessed as raw BSON via the Current field. For more information about change streams, see https://docs.mongodb.com/manual/changeStreams/.

func (*ChangeStream) Close 

func (cs *ChangeStream) Close(ctx context.Context) error

Close closes this change stream and the underlying cursor. Next and TryNext must not be called after Close has been called. Close is idempotent. After the first call, any subsequent calls will not change the state.

func (*ChangeStream) Decode 

func (cs *ChangeStream) Decode(val interface{}) error

Decode will unmarshal the current event document into val and return any errors from the unmarshalling process without any modification. If val is nil or is a typed nil, an error will be returned.

func (*ChangeStream) Err 

func (cs *ChangeStream) Err() error

Err returns the last error seen by the change stream, or nil if no errors has occurred.

func (*ChangeStream) ID 

func (cs *ChangeStream) ID() int64

ID returns the ID for this change stream, or 0 if the cursor has been closed or exhausted.

func (*ChangeStream) Next 

func (cs *ChangeStream) Next(ctx context.Context) bool

Next gets the next event for this change stream. It returns true if there were no errors and the next event document is available.

Next blocks until an event is available, an error occurs, or ctx expires. If ctx expires, the error will be set to ctx.Err(). In an error case, Next will return false.

If Next returns false, subsequent calls will also return false.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var stream *mongo.ChangeStream
	defer stream.Close(context.TODO())

	// Iterate the change stream and print out each event.
	// Because the Next call blocks until an event is available, another way to iterate the change stream is to call
	// Next in a goroutine and pass in a context that can be cancelled to abort the call.

	for stream.Next(context.TODO()) {
		// A new event variable should be declared for each event.
		var event bson.M
		if err := stream.Decode(&event); err != nil {
			log.Fatal(err)
		}
		fmt.Println(event)
	}
	if err := stream.Err(); err != nil {
		log.Fatal(err)
	}
}

Output:

func (*ChangeStream) ResumeToken 

func (cs *ChangeStream) ResumeToken() bson.Raw

ResumeToken returns the last cached resume token for this change stream, or nil if a resume token has not been stored.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"sync"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var client *mongo.Client
	var stream *mongo.ChangeStream // assume stream was created via client.Watch()

	cancelCtx, cancel := context.WithCancel(context.TODO())
	defer cancel()
	var wg sync.WaitGroup
	wg.Add(1)

	// Run a goroutine to process events.
	go func() {
		for stream.Next(cancelCtx) {
			fmt.Println(stream.Current)
		}
		wg.Done()
	}()

	// Assume client needs to be disconnected. Cancel the context being used by the goroutine to abort any
	// in-progres Next calls and wait for the goroutine to exit.
	cancel()
	wg.Wait()

	// Before disconnecting the client, store the last seen resume token for the change stream.
	resumeToken := stream.ResumeToken()
	_ = client.Disconnect(context.TODO())

	// Once a new client is created, the change stream can be re-created. Specify resumeToken as the ResumeAfter option
	// so only events that occurred after resumeToken will be returned.
	var newClient *mongo.Client
	opts := options.ChangeStream().SetResumeAfter(resumeToken)
	newStream, err := newClient.Watch(context.TODO(), mongo.Pipeline{}, opts)
	if err != nil {
		log.Fatal(err)
	}
	defer newStream.Close(context.TODO())
}

Output:

func (*ChangeStream) TryNext 

func (cs *ChangeStream) TryNext(ctx context.Context) bool

TryNext attempts to get the next event for this change stream. It returns true if there were no errors and the next event document is available.

TryNext returns false if the change stream is closed by the server, an error occurs when getting changes from the server, the next change is not yet available, or ctx expires. If ctx expires, the error will be set to ctx.Err().

If TryNext returns false and an error occurred or the change stream was closed (i.e. cs.Err() != nil || cs.ID() == 0), subsequent attempts will also return false. Otherwise, it is safe to call TryNext again until a change is available.

This method requires driver version >= 1.2.0.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var stream *mongo.ChangeStream
	defer stream.Close(context.TODO())

	// Iterate the change stream and print out each event until the change stream is closed by the server or there is an
	// error getting the next event.
	for {
		if stream.TryNext(context.TODO()) {
			// A new event variable should be declared for each event.
			var event bson.M
			if err := stream.Decode(&event); err != nil {
				log.Fatal(err)
			}
			fmt.Println(event)
			continue
		}

		// If TryNext returns false, the next change is not yet available, the change stream was closed by the server,
		// or an error occurred. TryNext should only be called again for the empty batch case.
		if err := stream.Err(); err != nil {
			log.Fatal(err)
		}
		if stream.ID() == 0 {
			break
		}
	}
}

Output:

type Client 

type Client struct {
	// contains filtered or unexported fields
}

Client is a handle representing a pool of connections to a MongoDB deployment. It is safe for concurrent use by multiple goroutines.

The Client type opens and closes connections automatically and maintains a pool of idle connections. For connection pool configuration options, see documentation for the ClientOptions type in the mongo/options package.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Create a Client and execute a ListDatabases operation.

	client, err := mongo.Connect(context.TODO(), options.Client().ApplyURI("mongodb://localhost:27017"))
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		if err = client.Disconnect(context.TODO()); err != nil {
			log.Fatal(err)
		}
	}()

	collection := client.Database("db").Collection("coll")
	result, err := collection.InsertOne(context.TODO(), bson.D{{"x", 1}})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("inserted ID: %v\n", result.InsertedID)
}

Output:

func Connect 

func Connect(ctx context.Context, opts ...*options.ClientOptions) (*Client, error)

Connect creates a new Client and then initializes it using the Connect method. This is equivalent to calling NewClient followed by Client.Connect.

When creating an options.ClientOptions, the order the methods are called matters. Later Set* methods will overwrite the values from previous Set* method invocations. This includes the ApplyURI method. This allows callers to determine the order of precedence for option application. For instance, if ApplyURI is called before SetAuth, the Credential from SetAuth will overwrite the values from the connection string. If ApplyURI is called after SetAuth, then its values will overwrite those from SetAuth.

The opts parameter is processed using options.MergeClientOptions, which will overwrite entire option fields of previous options, there is no partial overwriting. For example, if Username is set in the Auth field for the first option, and Password is set for the second but with no Username, after the merge the Username field will be empty.

The NewClient function does not do any I/O and returns an error if the given options are invalid. The Client.Connect method starts background goroutines to monitor the state of the deployment and does not do any I/O in the main goroutine to prevent the main goroutine from blocking. Therefore, it will not error if the deployment is down.

The Client.Ping method can be used to verify that the deployment is successfully connected and the Client was correctly configured.

Example (Direct) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Create a direct connection to a host. The driver will send all requests to that host and will not
	// automatically discover other hosts in the deployment.

	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017/?connect=direct")
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (Kerberos) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Configure a Client with GSSAPI/SSPI authentication (https://docs.mongodb.com/manual/core/kerberos/).
	// MongoDB Enterprise supports proxy authentication through a Kerberos service.
	// Using Kerberos authentication requires the "gssapi" build tag and cgo support during compilation.
	// The default service name for Kerberos is "mongodb". This can be configured via the AuthMechanismProperties
	// field in the options.Credential struct or the authMechanismProperties URI parameter.

	// For Linux, the libkrb5 library is required.
	// Users can authenticate in one of two ways:
	// 1. Use an explicit password. In this case, a password must be specified in the URI or the options.Credential
	// struct and no further setup is required.
	// 2. Store authentication keys in keytab files. To do this, the kinit binary should be used to initialize a
	// credential cache for authenticating the user principal. In this example, the invocation would be
	// "kinit drivers@KERBEROS.EXAMPLE.COM".

	// To configure auth via a URI instead of a Credential, use
	// "mongodb://drivers%40KERBEROS.EXAMPLE.COM@mongo-server.example.com:27017/?authMechanism=GSSAPI".
	credential := options.Credential{
		AuthMechanism: "GSSAPI",
		Username:      "drivers@KERBEROS.EXAMPLE.COM",
	}
	uri := "mongo-server.example.com:27017"
	clientOpts := options.Client().ApplyURI(uri).SetAuth(credential)

	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (PLAIN) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Configure a Client with LDAP authentication
	// (https://docs.mongodb.com/manual/core/authentication-mechanisms-enterprise/#security-auth-ldap).
	// MongoDB Enterprise supports proxy authentication through an LDAP service that can be used through the PLAIN
	// authentication mechanism.
	// This auth mechanism sends the password in plaintext and therefore should only be used with TLS connections.

	// To configure auth via a URI instead of a Credential, use
	// "mongodb://ldap-user:ldap-pwd@localhost:27017/?authMechanism=PLAIN".
	credential := options.Credential{
		AuthMechanism: "PLAIN",
		Username:      "ldap-user",
		Password:      "ldap-pwd",
	}
	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017").SetAuth(credential)

	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (Ping) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"go.mongodb.org/mongo-driver/mongo/readpref"
)

func main() {
	// Create a Client to a MongoDB server and use Ping to verify that the server is running.

	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017")
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	defer func() {
		if err = client.Disconnect(context.TODO()); err != nil {
			log.Fatal(err)
		}
	}()

	// Call Ping to verify that the deployment is up and the Client was configured successfully.
	// As mentioned in the Ping documentation, this reduces application resiliency as the server may be
	// temporarily unavailable when Ping is called.
	if err = client.Ping(context.TODO(), readpref.Primary()); err != nil {
		log.Fatal(err)
	}
}

Output:
Example (ReplicaSet) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Create and connect a Client to a replica set deployment.
	// Given this URI, the Go driver will first communicate with localhost:27017 and use the response to discover
	// any other members in the replica set.
	// The URI in this example specifies multiple members of the replica set to increase resiliency as one of the
	// members may be down when the application is started.

	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017,localhost:27018/?replicaSet=replset")
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (SCRAM) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Configure a Client with SCRAM authentication (https://docs.mongodb.com/manual/core/security-scram/).
	// The default authentication database for SCRAM is "admin". This can be configured via the
	// authSource query parameter in the URI or the AuthSource field in the options.Credential struct.
	// SCRAM is the default auth mechanism so specifying a mechanism is not required.

	// To configure auth via URI instead of a Credential, use
	// "mongodb://user:password@localhost:27017".
	credential := options.Credential{
		Username: "user",
		Password: "password",
	}
	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017").SetAuth(credential)
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (SRV) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Create and connect a Client using an SRV record.
	// SRV records allow administrators to configure a single domain to return a list of host names.
	// The driver will resolve SRV records prefixed with "_mongodb_tcp" and use the returned host names to
	// build its view of the deployment.
	// See https://docs.mongodb.com/manual/reference/connection-string/ for more information about SRV.
	// Full support for SRV records with sharded clusters requires driver version 1.1.0 or higher.

	clientOpts := options.Client().ApplyURI("mongodb+srv://mongodb.example.com")
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (Sharded) 
package main

import (
	"context"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Create and connect a Client to a sharded deployment.
	// The URI for a sharded deployment should specify the mongos servers that the application wants to send
	// messages to.

	clientOpts := options.Client().ApplyURI("mongodb://localhost:27017,localhost:27018")
	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:
Example (X509) 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	// Configure a Client with X509 authentication (https://docs.mongodb.com/manual/core/security-x.509/).

	// X509 can be configured with different sets of options in the connection string:
	// 1. tlsCAFile (or SslCertificateAuthorityFile): Path to the file with either a single or bundle of certificate
	// authorities to be considered trusted when making a TLS connection.
	// 2. tlsCertificateKeyFile (or SslClientCertificateKeyFile): Path to the client certificate file or the client
	// private key file. In the case that both are needed, the files should be concatenated.

	// The SetAuth client option should also be used. The username field is optional. If it is not specified, it will
	// be extracted from the certificate key file. The AuthSource is required to be $external.

	caFilePath := "path/to/cafile"
	certificateKeyFilePath := "path/to/client-certificate"

	// To configure auth via a URI instead of a Credential, append "&authMechanism=MONGODB-X509" to the URI.
	uri := "mongodb://host:port/?tlsCAFile=%s&tlsCertificateKeyFile=%s"
	uri = fmt.Sprintf(uri, caFilePath, certificateKeyFilePath)
	credential := options.Credential{
		AuthMechanism: "MONGODB-X509",
	}
	clientOpts := options.Client().ApplyURI(uri).SetAuth(credential)

	client, err := mongo.Connect(context.TODO(), clientOpts)
	if err != nil {
		log.Fatal(err)
	}
	_ = client
}

Output:

func NewClient 

func NewClient(opts ...*options.ClientOptions) (*Client, error)

NewClient creates a new client to connect to a deployment specified by the uri.

When creating an options.ClientOptions, the order the methods are called matters. Later Set* methods will overwrite the values from previous Set* method invocations. This includes the ApplyURI method. This allows callers to determine the order of precedence for option application. For instance, if ApplyURI is called before SetAuth, the Credential from SetAuth will overwrite the values from the connection string. If ApplyURI is called after SetAuth, then its values will overwrite those from SetAuth.

The opts parameter is processed using options.MergeClientOptions, which will overwrite entire option fields of previous options, there is no partial overwriting. For example, if Username is set in the Auth field for the first option, and Password is set for the second but with no Username, after the merge the Username field will be empty.

func (*Client) Connect 

func (c *Client) Connect(ctx context.Context) error

Connect initializes the Client by starting background monitoring goroutines. If the Client was created using the NewClient function, this method must be called before a Client can be used.

Connect starts background goroutines to monitor the state of the deployment and does not do any I/O in the main goroutine. The Client.Ping method can be used to verify that the connection was created successfully.

func (*Client) Database 

func (c *Client) Database(name string, opts ...*options.DatabaseOptions) *Database

Database returns a handle for a database with the given name configured with the given DatabaseOptions.

func (*Client) Disconnect 

func (c *Client) Disconnect(ctx context.Context) error

Disconnect closes sockets to the topology referenced by this Client. It will shut down any monitoring goroutines, close the idle connection pool, and will wait until all the in use connections have been returned to the connection pool and closed before returning. If the context expires via cancellation, deadline, or timeout before the in use connections have returned, the in use connections will be closed, resulting in the failure of any in flight read or write operations. If this method returns with no errors, all connections associated with this Client have been closed.

func (*Client) ListDatabaseNames 

func (c *Client) ListDatabaseNames(ctx context.Context, filter interface{}, opts ...*options.ListDatabasesOptions) ([]string, error)

ListDatabaseNames executes a listDatabases command and returns a slice containing the names of all of the databases on the server.

The filter parameter must be a document containing query operators and can be used to select which databases are included in the result. It cannot be nil. An empty document (e.g. bson.D{}) should be used to include all databases.

The opts parameter can be used to specify options for this operation (see the options.ListDatabasesOptions documentation.)

For more information about the command, see https://docs.mongodb.com/manual/reference/command/listDatabases/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var client *mongo.Client

	// use a filter to only select non-empty databases
	result, err := client.ListDatabaseNames(context.TODO(), bson.D{{"empty", false}})
	if err != nil {
		log.Fatal(err)
	}

	for _, db := range result {
		fmt.Println(db)
	}
}

Output:

func (*Client) ListDatabases 

func (c *Client) ListDatabases(ctx context.Context, filter interface{}, opts ...*options.ListDatabasesOptions) (ListDatabasesResult, error)

ListDatabases executes a listDatabases command and returns the result.

The filter parameter must be a document containing query operators and can be used to select which databases are included in the result. It cannot be nil. An empty document (e.g. bson.D{}) should be used to include all databases.

The opts paramter can be used to specify options for this operation (see the options.ListDatabasesOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/listDatabases/.

func (*Client) NumberSessionsInProgress 

func (c *Client) NumberSessionsInProgress() int

NumberSessionsInProgress returns the number of sessions that have been started for this client but have not been closed (i.e. EndSession has not been called).

func (*Client) Ping 

func (c *Client) Ping(ctx context.Context, rp *readpref.ReadPref) error

Ping sends a ping command to verify that the client can connect to the deployment.

The rp paramter is used to determine which server is selected for the operation. If it is nil, the client's read preference is used.

If the server is down, Ping will try to select a server until the client's server selection timeout expires. This can be configured through the ClientOptions.SetServerSelectionTimeout option when creating a new Client. After the timeout expires, a server selection error is returned.

Using Ping reduces application resilience because applications starting up will error if the server is temporarily unavailable or is failing over (e.g. during autoscaling due to a load spike).

func (*Client) StartSession 

func (c *Client) StartSession(opts ...*options.SessionOptions) (Session, error)

StartSession starts a new session configured with the given options.

If the DefaultReadConcern, DefaultWriteConcern, or DefaultReadPreference options are not set, the client's read concern, write concern, or read preference will be used, respectively.

Example (WithTransaction) 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"go.mongodb.org/mongo-driver/mongo/readconcern"
	"go.mongodb.org/mongo-driver/mongo/readpref"
)

func main() {
	var client *mongo.Client // assume client is configured with write concern majority and read preference primary

	// Specify the DefaultReadConcern option so any transactions started through the session will have read concern
	// majority.
	// The DefaultReadPreference and DefaultWriteConcern options aren't specified so they will be inheritied from client
	// and be set to primary and majority, respectively.
	opts := options.Session().SetDefaultReadConcern(readconcern.Majority())
	sess, err := client.StartSession(opts)
	if err != nil {
		log.Fatal(err)
	}
	defer sess.EndSession(context.TODO())

	// Specify the ReadPreference option to set the read preference to primary preferred for this transaction.
	txnOpts := options.Transaction().SetReadPreference(readpref.PrimaryPreferred())
	result, err := sess.WithTransaction(context.TODO(), func(sessCtx mongo.SessionContext) (interface{}, error) {
		// Use sessCtx as the Context parameter for InsertOne and FindOne so both operations are run in a
		// transaction.

		coll := client.Database("db").Collection("coll")
		res, err := coll.InsertOne(sessCtx, bson.D{{"x", 1}})
		if err != nil {
			return nil, err
		}

		var result bson.M
		if err = coll.FindOne(sessCtx, bson.D{{"_id", res.InsertedID}}).Decode(result); err != nil {
			return nil, err
		}
		return result, err
	}, txnOpts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("result: %v\n", result)
}

Output:

func (*Client) UseSession 

func (c *Client) UseSession(ctx context.Context, fn func(SessionContext) error) error

UseSession creates a new Session and uses it to create a new SessionContext, which is used to call the fn callback. The SessionContext parameter must be used as the Context parameter for any operations in the fn callback that should be executed under a session. After the callback returns, the created Session is ended, meaning that any in-progress transactions started by fn will be aborted even if fn returns an error.

If the ctx parameter already contains a Session, that Session will be replaced with the newly created one.

Any error returned by the fn callback will be returned without any modifications.

func (*Client) UseSessionWithOptions 

func (c *Client) UseSessionWithOptions(ctx context.Context, opts *options.SessionOptions, fn func(SessionContext) error) error

UseSessionWithOptions operates like UseSession but uses the given SessionOptions to create the Session.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"go.mongodb.org/mongo-driver/mongo/readconcern"
)

func main() {
	var client *mongo.Client

	// Specify the DefaultReadConcern option so any transactions started through the session will have read concern
	// majority.
	// The DefaultReadPreference and DefaultWriteConcern options aren't specified so they will be inheritied from client
	// and be set to primary and majority, respectively.
	opts := options.Session().SetDefaultReadConcern(readconcern.Majority())
	err := client.UseSessionWithOptions(context.TODO(), opts, func(sessCtx mongo.SessionContext) error {
		// Use sessCtx as the Context parameter for InsertOne and FindOne so both operations are run under the new
		// Session.

		coll := client.Database("db").Collection("coll")
		res, err := coll.InsertOne(sessCtx, bson.D{{"x", 1}})
		if err != nil {
			return err
		}

		var result bson.M
		if err = coll.FindOne(sessCtx, bson.D{{"_id", res.InsertedID}}).Decode(result); err != nil {
			return err
		}
		fmt.Println(result)
		return nil
	})
	if err != nil {
		log.Fatal(err)
	}
}

Output:

func (*Client) Watch 

func (c *Client) Watch(ctx context.Context, pipeline interface{},
	opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

Watch returns a change stream for all changes on the deployment. See https://docs.mongodb.com/manual/changeStreams/ for more information about change streams.

The client must be configured with read concern majority or no read concern for a change stream to be created successfully.

The pipeline parameter must be an array of documents, each representing a pipeline stage. The pipeline cannot be nil or empty. The stage documents must all be non-nil. See https://docs.mongodb.com/manual/changeStreams/ for a list of pipeline stages that can be used with change streams. For a pipeline of bson.D documents, the mongo.Pipeline{} type can be used.

The opts parameter can be used to specify options for change stream creation (see the options.ChangeStreamOptions documentation).

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var client *mongo.Client

	// specify a pipeline that will only match "insert" events
	// specify the MaxAwaitTimeOption to have each attempt wait two seconds for new documents
	matchStage := bson.D{{"$match", bson.D{{"operationType", "insert"}}}}
	opts := options.ChangeStream().SetMaxAwaitTime(2 * time.Second)
	changeStream, err := client.Watch(context.TODO(), mongo.Pipeline{matchStage}, opts)
	if err != nil {
		log.Fatal(err)
	}

	// print out all change stream events in the order they're received
	// see the mongo.ChangeStream documentation for more examples of using change streams
	for changeStream.Next(context.TODO()) {
		fmt.Println(changeStream.Current)
	}
}

Output:

type ClientEncryption 

type ClientEncryption struct {
	// contains filtered or unexported fields
}

ClientEncryption is used to create data keys and explicitly encrypt and decrypt BSON values.

func NewClientEncryption 

func NewClientEncryption(keyVaultClient *Client, opts ...*options.ClientEncryptionOptions) (*ClientEncryption, error)

NewClientEncryption creates a new ClientEncryption instance configured with the given options.

func (*ClientEncryption) Close 

func (ce *ClientEncryption) Close(ctx context.Context) error

Close cleans up any resources associated with the ClientEncryption instance. This includes disconnecting the key-vault Client instance.

func (*ClientEncryption) CreateDataKey 

func (ce *ClientEncryption) CreateDataKey(ctx context.Context, kmsProvider string, opts ...*options.DataKeyOptions) (primitive.Binary, error)

CreateDataKey creates a new key document and inserts it into the key vault collection. Returns the _id of the created document.

func (*ClientEncryption) Decrypt 

func (ce *ClientEncryption) Decrypt(ctx context.Context, val primitive.Binary) (bson.RawValue, error)

Decrypt decrypts an encrypted value (BSON binary of subtype 6) and returns the original BSON value.

func (*ClientEncryption) Encrypt 

func (ce *ClientEncryption) Encrypt(ctx context.Context, val bson.RawValue, opts ...*options.EncryptOptions) (primitive.Binary, error)

Encrypt encrypts a BSON value with the given key and algorithm. Returns an encrypted value (BSON binary of subtype 6).

type Collection 

type Collection struct {
	// contains filtered or unexported fields
}

Collection is a handle to a MongoDB collection. It is safe for concurrent use by multiple goroutines.

func (*Collection) Aggregate 

func (coll *Collection) Aggregate(ctx context.Context, pipeline interface{},
	opts ...*options.AggregateOptions) (*Cursor, error)

Aggregate executes an aggregate command against the collection and returns a cursor over the resulting documents.

The pipeline parameter must be an array of documents, each representing an aggregation stage. The pipeline cannot be nil but can be empty. The stage documents must all be non-nil. For a pipeline of bson.D documents, the mongo.Pipeline type can be used. See https://docs.mongodb.com/manual/reference/operator/aggregation-pipeline/#db-collection-aggregate-stages for a list of valid stages in aggregations.

The opts parameter can be used to specify options for the operation (see the options.AggregateOptions documentation.)

For more information about the command, see https://docs.mongodb.com/manual/reference/command/aggregate/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// specify a pipeline that will return the number of times each name appears in the collection
	// specify the MaxTime option to limit the amount of time the operation can run on the server
	groupStage := bson.D{
		{"$group", bson.D{
			{"_id", "$name"},
			{"numTimes", bson.D{
				{"$sum", 1},
			}},
		}},
	}
	opts := options.Aggregate().SetMaxTime(2 * time.Second)
	cursor, err := coll.Aggregate(context.TODO(), mongo.Pipeline{groupStage}, opts)
	if err != nil {
		log.Fatal(err)
	}

	// get a list of all returned documents and print them out
	// see the mongo.Cursor documentation for more examples of using cursors
	var results []bson.M
	if err = cursor.All(context.TODO(), &results); err != nil {
		log.Fatal(err)
	}
	for _, result := range results {
		fmt.Printf("name %v appears %v times\n", result["_id"], result["numTimes"])
	}
}

Output:

func (*Collection) BulkWrite 

func (coll *Collection) BulkWrite(ctx context.Context, models []WriteModel,
	opts ...*options.BulkWriteOptions) (*BulkWriteResult, error)

BulkWrite performs a bulk write operation (https://docs.mongodb.com/manual/core/bulk-write-operations/).

The models parameter must be a slice of operations to be executed in this bulk write. It cannot be nil or empty. All of the models must be non-nil. See the mongo.WriteModel documentation for a list of valid model types and examples of how they should be used.

The opts parameter can be used to specify options for the operation (see the options.BulkWriteOptions documentation.)

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var firstID, secondID primitive.ObjectID

	// update the "email" field for two users
	// for each update, specify the Upsert option to insert a new document if a document matching the filter isn't
	// found
	// set the Ordered option to false to allow both operations to happen even if one of them errors
	firstUpdate := bson.D{{"$set", bson.D{{"email", "firstEmail@example.com"}}}}
	secondUpdate := bson.D{{"$set", bson.D{{"email", "secondEmail@example.com"}}}}
	models := []mongo.WriteModel{
		mongo.NewUpdateOneModel().SetFilter(bson.D{{"_id", firstID}}).SetUpdate(firstUpdate).SetUpsert(true),
		mongo.NewUpdateOneModel().SetFilter(bson.D{{"_id", secondID}}).SetUpdate(secondUpdate).SetUpsert(true),
	}
	opts := options.BulkWrite().SetOrdered(false)
	res, err := coll.BulkWrite(context.TODO(), models, opts)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("inserted %v and deleted %v documents\n", res.InsertedCount, res.DeletedCount)
}

Output:

func (*Collection) Clone 

func (coll *Collection) Clone(opts ...*options.CollectionOptions) (*Collection, error)

Clone creates a copy of the Collection configured with the given CollectionOptions. The specified options are merged with the existing options on the collection, with the specified options taking precedence.

func (*Collection) CountDocuments 

func (coll *Collection) CountDocuments(ctx context.Context, filter interface{},
	opts ...*options.CountOptions) (int64, error)

CountDocuments returns the number of documents in the collection. For a fast count of the documents in the collection, see the EstimatedDocumentCount method.

The filter parameter must be a document and can be used to select which documents contribute to the count. It cannot be nil. An empty document (e.g. bson.D{}) should be used to count all documents in the collection. This will result in a full collection scan.

The opts parameter can be used to specify options for the operation (see the options.CountOptions documentation).

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// count the number of times the name "Bob" appears in the collection
	// specify the MaxTime option to limit the amount of time the operation can run on the server
	opts := options.Count().SetMaxTime(2 * time.Second)
	count, err := coll.CountDocuments(context.TODO(), bson.D{{"name", "Bob"}}, opts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("name Bob appears in %v documents", count)
}

Output:

func (*Collection) Database 

func (coll *Collection) Database() *Database

Database returns the Database that was used to create the Collection.

func (*Collection) DeleteMany 

func (coll *Collection) DeleteMany(ctx context.Context, filter interface{},
	opts ...*options.DeleteOptions) (*DeleteResult, error)

DeleteMany executes a delete command to delete documents from the collection.

The filter parameter must be a document containing query operators and can be used to select the documents to be deleted. It cannot be nil. An empty document (e.g. bson.D{}) should be used to delete all documents in the collection. If the filter does not match any documents, the operation will succeed and a DeleteResult with a DeletedCount of 0 will be returned.

The opts parameter can be used to specify options for the operation (see the options.DeleteOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/delete/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// delete all documents in which the "name" field is "Bob" or "bob"
	// specify the Collation option to provide a collation that will ignore case for string comparisons
	opts := options.Delete().SetCollation(&options.Collation{
		Locale:    "en_US",
		Strength:  1,
		CaseLevel: false,
	})
	res, err := coll.DeleteMany(context.TODO(), bson.D{{"name", "bob"}}, opts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("deleted %v documents\n", res.DeletedCount)
}

Output:

func (*Collection) DeleteOne 

func (coll *Collection) DeleteOne(ctx context.Context, filter interface{},
	opts ...*options.DeleteOptions) (*DeleteResult, error)

DeleteOne executes a delete command to delete at most one document from the collection.

The filter parameter must be a document containing query operators and can be used to select the document to be deleted. It cannot be nil. If the filter does not match any documents, the operation will succeed and a DeleteResult with a DeletedCount of 0 will be returned. If the filter matches multiple documents, one will be selected from the matched set.

The opts parameter can be used to specify options for the operation (see the options.DeleteOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/delete/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// delete at most one document in which the "name" field is "Bob" or "bob"
	// specify the SetCollation option to provide a collation that will ignore case for string comparisons
	opts := options.Delete().SetCollation(&options.Collation{
		Locale:    "en_US",
		Strength:  1,
		CaseLevel: false,
	})
	res, err := coll.DeleteOne(context.TODO(), bson.D{{"name", "bob"}}, opts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("deleted %v documents\n", res.DeletedCount)
}

Output:

func (*Collection) Distinct 

func (coll *Collection) Distinct(ctx context.Context, fieldName string, filter interface{},
	opts ...*options.DistinctOptions) ([]interface{}, error)

Distinct executes a distinct command to find the unique values for a specified field in the collection.

The fieldName parameter specifies the field name for which distinct values should be returned.

The filter parameter must be a document containing query operators and can be used to select which documents are considered. It cannot be nil. An empty document (e.g. bson.D{}) should be used to select all documents.

The opts parameter can be used to specify options for the operation (see the options.DistinctOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/distinct/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// find all unique values for the "name" field for documents in which the "age" field is greater than 25
	// specify the MaxTime option to limit the amount of time the operation can run on the server
	filter := bson.D{{"age", bson.D{{"$gt", 25}}}}
	opts := options.Distinct().SetMaxTime(2 * time.Second)
	values, err := coll.Distinct(context.TODO(), "name", filter, opts)
	if err != nil {
		log.Fatal(err)
	}

	for _, value := range values {
		fmt.Println(value)
	}
}

Output:

func (*Collection) Drop 

func (coll *Collection) Drop(ctx context.Context) error

Drop drops the collection on the server. This method ignores "namespace not found" errors so it is safe to drop a collection that does not exist on the server.

func (*Collection) EstimatedDocumentCount 

func (coll *Collection) EstimatedDocumentCount(ctx context.Context,
	opts ...*options.EstimatedDocumentCountOptions) (int64, error)

EstimatedDocumentCount executes a count command and returns an estimate of the number of documents in the collection using collection metadata.

The opts parameter can be used to specify options for the operation (see the options.EstimatedDocumentCountOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/count/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// get and print an estimated of the number of documents in the collection
	// specify the MaxTime option to limit the amount of time the operation can run on the server
	opts := options.EstimatedDocumentCount().SetMaxTime(2 * time.Second)
	count, err := coll.EstimatedDocumentCount(context.TODO(), opts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("estimated document count: %v", count)
}

Output:

func (*Collection) Find 

func (coll *Collection) Find(ctx context.Context, filter interface{},
	opts ...*options.FindOptions) (*Cursor, error)

Find executes a find command and returns a Cursor over the matching documents in the collection.

The filter parameter must be a document containing query operators and can be used to select which documents are included in the result. It cannot be nil. An empty document (e.g. bson.D{}) should be used to include all documents.

The opts parameter can be used to specify options for the operation (see the options.FindOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/find/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// find all documents in which the "name" field is "Bob"
	// specify the Sort option to sort the returned documents by age in ascending order
	opts := options.Find().SetSort(bson.D{{"age", 1}})
	cursor, err := coll.Find(context.TODO(), bson.D{{"name", "Bob"}}, opts)
	if err != nil {
		log.Fatal(err)
	}

	// get a list of all returned documents and print them out
	// see the mongo.Cursor documentation for more examples of using cursors
	var results []bson.M
	if err = cursor.All(context.TODO(), &results); err != nil {
		log.Fatal(err)
	}
	for _, result := range results {
		fmt.Println(result)
	}
}

Output:

func (*Collection) FindOne 

func (coll *Collection) FindOne(ctx context.Context, filter interface{},
	opts ...*options.FindOneOptions) *SingleResult

FindOne executes a find command and returns a SingleResult for one document in the collection.

The filter parameter must be a document containing query operators and can be used to select the document to be returned. It cannot be nil. If the filter does not match any documents, a SingleResult with an error set to ErrNoDocuments will be returned. If the filter matches multiple documents, one will be selected from the matched set.

The opts parameter can be used to specify options for this operation (see the options.FindOneOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/find/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find the document for which the _id field matches id
	// specify the Sort option to sort the documents by age
	// the first document in the sorted order will be returned
	opts := options.FindOne().SetSort(bson.D{{"age", 1}})
	var result bson.M
	err := coll.FindOne(context.TODO(), bson.D{{"_id", id}}, opts).Decode(&result)
	if err != nil {
		// ErrNoDocuments means that the filter did not match any documents in the collection
		if err == mongo.ErrNoDocuments {
			return
		}
		log.Fatal(err)
	}
	fmt.Printf("found document %v", result)
}

Output:

func (*Collection) FindOneAndDelete 

func (coll *Collection) FindOneAndDelete(ctx context.Context, filter interface{},
	opts ...*options.FindOneAndDeleteOptions) *SingleResult

FindOneAndDelete executes a findAndModify command to delete at most one document in the collection. and returns the document as it appeared before deletion.

The filter parameter must be a document containing query operators and can be used to select the document to be deleted. It cannot be nil. If the filter does not match any documents, a SingleResult with an error set to ErrNoDocuments wil be returned. If the filter matches multiple documents, one will be selected from the matched set.

The opts parameter can be used to specify options for the operation (see the options.FindOneAndDeleteOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/findAndModify/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find and delete the document for which the _id field matches id
	// specify the Projection option to only include the name and age fields in the returned document
	opts := options.FindOneAndDelete().SetProjection(bson.D{{"name", 1}, {"age", 1}})
	var deletedDocument bson.M
	err := coll.FindOneAndDelete(context.TODO(), bson.D{{"_id", id}}, opts).Decode(&deletedDocument)
	if err != nil {
		// ErrNoDocuments means that the filter did not match any documents in the collection
		if err == mongo.ErrNoDocuments {
			return
		}
		log.Fatal(err)
	}
	fmt.Printf("deleted document %v", deletedDocument)
}

Output:

func (*Collection) FindOneAndReplace 

func (coll *Collection) FindOneAndReplace(ctx context.Context, filter interface{},
	replacement interface{}, opts ...*options.FindOneAndReplaceOptions) *SingleResult

FindOneAndReplace executes a findAndModify command to replace at most one document in the collection and returns the document as it appeared before replacement.

The filter parameter must be a document containing query operators and can be used to select the document to be replaced. It cannot be nil. If the filter does not match any documents, a SingleResult with an error set to ErrNoDocuments wil be returned. If the filter matches multiple documents, one will be selected from the matched set.

The replacement parameter must be a document that will be used to replace the selected document. It cannot be nil and cannot contain any update operators (https://docs.mongodb.com/manual/reference/operator/update/).

The opts parameter can be used to specify options for the operation (see the options.FindOneAndReplaceOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/findAndModify/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find the document for which the _id field matches id and add a field called "location"
	// specify the Upsert option to insert a new document if a document matching the filter isn't found
	opts := options.FindOneAndReplace().SetUpsert(true)
	filter := bson.D{{"_id", id}}
	replacement := bson.D{{"location", "NYC"}}
	var replacedDocument bson.M
	err := coll.FindOneAndReplace(context.TODO(), filter, replacement, opts).Decode(&replacedDocument)
	if err != nil {
		// ErrNoDocuments means that the filter did not match any documents in the collection
		if err == mongo.ErrNoDocuments {
			return
		}
		log.Fatal(err)
	}
	fmt.Printf("replaced document %v", replacedDocument)
}

Output:

func (*Collection) FindOneAndUpdate 

func (coll *Collection) FindOneAndUpdate(ctx context.Context, filter interface{},
	update interface{}, opts ...*options.FindOneAndUpdateOptions) *SingleResult

FindOneAndUpdate executes a findAndModify command to update at most one document in the collection and returns the document as it appeared before updating.

The filter parameter must be a document containing query operators and can be used to select the document to be updated. It cannot be nil. If the filter does not match any documents, a SingleResult with an error set to ErrNoDocuments wil be returned. If the filter matches multiple documents, one will be selected from the matched set.

The update parameter must be a document containing update operators (https://docs.mongodb.com/manual/reference/operator/update/) and can be used to specify the modifications to be made to the selected document. It cannot be nil or empty.

The opts parameter can be used to specify options for the operation (see the options.FindOneAndUpdateOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/findAndModify/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find the document for which the _id field matches id and set the email to "newemail@example.com"
	// specify the Upsert option to insert a new document if a document matching the filter isn't found
	opts := options.FindOneAndUpdate().SetUpsert(true)
	filter := bson.D{{"_id", id}}
	update := bson.D{{"$set", bson.D{{"email", "newemail@example.com"}}}}
	var updatedDocument bson.M
	err := coll.FindOneAndUpdate(context.TODO(), filter, update, opts).Decode(&updatedDocument)
	if err != nil {
		// ErrNoDocuments means that the filter did not match any documents in the collection
		if err == mongo.ErrNoDocuments {
			return
		}
		log.Fatal(err)
	}
	fmt.Printf("updated document %v", updatedDocument)
}

Output:

func (*Collection) Indexes 

func (coll *Collection) Indexes() IndexView

Indexes returns an IndexView instance that can be used to perform operations on the indexes for the collection.

func (*Collection) InsertMany 

func (coll *Collection) InsertMany(ctx context.Context, documents []interface{},
	opts ...*options.InsertManyOptions) (*InsertManyResult, error)

InsertMany executes an insert command to insert multiple documents into the collection. If write errors occur during the operation (e.g. duplicate key error), this method returns a BulkWriteException error.

The documents parameter must be a slice of documents to insert. The slice cannot be nil or empty. The elements must all be non-nil. For any document that does not have an _id field when transformed into BSON, one will be added automatically to the marshalled document. The original document will not be modified. The _id values for the inserted documents can be retrieved from the InsertedIDs field of the returnd InsertManyResult.

The opts parameter can be used to specify options for the operation (see the options.InsertManyOptions documentation.)

For more information about the command, see https://docs.mongodb.com/manual/reference/command/insert/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection

	// insert documents {name: "Alice"} and {name: "Bob"}
	// set the Ordered option to false to allow both operations to happen even if one of them errors
	docs := []interface{}{
		bson.D{{"name", "Alice"}},
		bson.D{{"name", "Bob"}},
	}
	opts := options.InsertMany().SetOrdered(false)
	res, err := coll.InsertMany(context.TODO(), docs, opts)
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("inserted documents with IDs %v\n", res.InsertedIDs)
}

Output:

func (*Collection) InsertOne 

func (coll *Collection) InsertOne(ctx context.Context, document interface{},
	opts ...*options.InsertOneOptions) (*InsertOneResult, error)

InsertOne executes an insert command to insert a single document into the collection.

The document parameter must be the document to be inserted. It cannot be nil. If the document does not have an _id field when transformed into BSON, one will be added automatically to the marshalled document. The original document will not be modified. The _id can be retrieved from the InsertedID field of the returned InsertOneResult.

The opts parameter can be used to specify options for the operation (see the options.InsertOneOptions documentation.)

For more information about the command, see https://docs.mongodb.com/manual/reference/command/insert/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var coll *mongo.Collection

	// insert the document {name: "Alice"}
	res, err := coll.InsertOne(context.TODO(), bson.D{{"name", "Alice"}})
	if err != nil {
		log.Fatal(err)
	}
	fmt.Printf("inserted document with ID %v\n", res.InsertedID)
}

Output:

func (*Collection) Name 

func (coll *Collection) Name() string

Name returns the name of the collection.

func (*Collection) ReplaceOne 

func (coll *Collection) ReplaceOne(ctx context.Context, filter interface{},
	replacement interface{}, opts ...*options.ReplaceOptions) (*UpdateResult, error)

ReplaceOne executes an update command to replace at most one document in the collection.

The filter parameter must be a document containing query operators and can be used to select the document to be replaced. It cannot be nil. If the filter does not match any documents, the operation will succeed and an UpdateResult with a MatchedCount of 0 will be returned. If the filter matches multiple documents, one will be selected from the matched set and MatchedCount will equal 1.

The replacement parameter must be a document that will be used to replace the selected document. It cannot be nil and cannot contain any update operators (https://docs.mongodb.com/manual/reference/operator/update/).

The opts parameter can be used to specify options for the operation (see the options.ReplaceOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/update/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find the document for which the _id field matches id and add a field called "location"
	// specify the Upsert option to insert a new document if a document matching the filter isn't found
	opts := options.Replace().SetUpsert(true)
	filter := bson.D{{"_id", id}}
	replacement := bson.D{{"location", "NYC"}}
	result, err := coll.ReplaceOne(context.TODO(), filter, replacement, opts)
	if err != nil {
		log.Fatal(err)
	}

	if result.MatchedCount != 0 {
		fmt.Println("matched and replaced an existing document")
		return
	}
	if result.UpsertedCount != 0 {
		fmt.Printf("inserted a new document with ID %v\n", result.UpsertedID)
	}
}

Output:

func (*Collection) UpdateMany 

func (coll *Collection) UpdateMany(ctx context.Context, filter interface{}, update interface{},
	opts ...*options.UpdateOptions) (*UpdateResult, error)

UpdateMany executes an update command to update documents in the collection.

The filter parameter must be a document containing query operators and can be used to select the documents to be updated. It cannot be nil. If the filter does not match any documents, the operation will succeed and an UpdateResult with a MatchedCount of 0 will be returned.

The update parameter must be a document containing update operators (https://docs.mongodb.com/manual/reference/operator/update/) and can be used to specify the modifications to be made to the selected documents. It cannot be nil or empty.

The opts parameter can be used to specify options for the operation (see the options.UpdateOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/update/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var coll *mongo.Collection

	// increment the age for all users whose birthday is today
	today := time.Now().Format("01-01-1970")
	filter := bson.D{{"birthday", today}}
	update := bson.D{{"$inc", bson.D{{"age", 1}}}}

	result, err := coll.UpdateMany(context.TODO(), filter, update)
	if err != nil {
		log.Fatal(err)
	}

	if result.MatchedCount != 0 {
		fmt.Println("matched and replaced an existing document")
		return
	}
}

Output:

func (*Collection) UpdateOne 

func (coll *Collection) UpdateOne(ctx context.Context, filter interface{}, update interface{},
	opts ...*options.UpdateOptions) (*UpdateResult, error)

UpdateOne executes an update command to update at most one document in the collection.

The filter parameter must be a document containing query operators and can be used to select the document to be updated. It cannot be nil. If the filter does not match any documents, the operation will succeed and an UpdateResult with a MatchedCount of 0 will be returned. If the filter matches multiple documents, one will be selected from the matched set and MatchedCount will equal 1.

The update parameter must be a document containing update operators (https://docs.mongodb.com/manual/reference/operator/update/) and can be used to specify the modifications to be made to the selected document. It cannot be nil or empty.

The opts parameter can be used to specify options for the operation (see the options.UpdateOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/update/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/bson/primitive"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var coll *mongo.Collection
	var id primitive.ObjectID

	// find the document for which the _id field matches id and set the email to "newemail@example.com"
	// specify the Upsert option to insert a new document if a document matching the filter isn't found
	opts := options.Update().SetUpsert(true)
	filter := bson.D{{"_id", id}}
	update := bson.D{{"$set", bson.D{{"email", "newemail@example.com"}}}}

	result, err := coll.UpdateOne(context.TODO(), filter, update, opts)
	if err != nil {
		log.Fatal(err)
	}

	if result.MatchedCount != 0 {
		fmt.Println("matched and replaced an existing document")
		return
	}
	if result.UpsertedCount != 0 {
		fmt.Printf("inserted a new document with ID %v\n", result.UpsertedID)
	}
}

Output:

func (*Collection) Watch 

func (coll *Collection) Watch(ctx context.Context, pipeline interface{},
	opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

Watch returns a change stream for all changes on the corresponding collection. See https://docs.mongodb.com/manual/changeStreams/ for more information about change streams.

The Collection must be configured with read concern majority or no read concern for a change stream to be created successfully.

The pipeline parameter must be an array of documents, each representing a pipeline stage. The pipeline cannot be nil but can be empty. The stage documents must all be non-nil. See https://docs.mongodb.com/manual/changeStreams/ for a list of pipeline stages that can be used with change streams. For a pipeline of bson.D documents, the mongo.Pipeline{} type can be used.

The opts parameter can be used to specify options for change stream creation (see the options.ChangeStreamOptions documentation).

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var collection *mongo.Collection

	// specify a pipeline that will only match "insert" events
	// specify the MaxAwaitTimeOption to have each attempt wait two seconds for new documents
	matchStage := bson.D{{"$match", bson.D{{"operationType", "insert"}}}}
	opts := options.ChangeStream().SetMaxAwaitTime(2 * time.Second)
	changeStream, err := collection.Watch(context.TODO(), mongo.Pipeline{matchStage}, opts)
	if err != nil {
		log.Fatal(err)
	}

	// print out all change stream events in the order they're received
	// see the mongo.ChangeStream documentation for more examples of using change streams
	for changeStream.Next(context.TODO()) {
		fmt.Println(changeStream.Current)
	}
}

Output:

type CommandError 

type CommandError struct {
	Code    int32
	Message string
	Labels  []string // Categories to which the error belongs
	Name    string   // A human-readable name corresponding to the error code
}

CommandError represents a server error during execution of a command. This can be returned by any operation.

func (CommandError) Error 

func (e CommandError) Error() string

Error implements the error interface.

func (CommandError) HasErrorLabel 

func (e CommandError) HasErrorLabel(label string) bool

HasErrorLabel returns true if the error contains the specified label.

func (CommandError) IsMaxTimeMSExpiredError 

func (e CommandError) IsMaxTimeMSExpiredError() bool

IsMaxTimeMSExpiredError returns true if the error is a MaxTimeMSExpired error.

type Cursor 

type Cursor struct {
	// Current contains the BSON bytes of the current change document. This property is only valid until the next call
	// to Next or TryNext. If continued access is required, a copy must be made.
	Current bson.Raw
	// contains filtered or unexported fields
}

Cursor is used to iterate over a stream of documents. Each document can be decoded into a Go type via the Decode method or accessed as raw BSON via the Current field.

func (*Cursor) All 

func (c *Cursor) All(ctx context.Context, results interface{}) error

All iterates the cursor and decodes each document into results. The results parameter must be a pointer to a slice. The slice pointed to by results will be completely overwritten. This method will close the cursor after retrieving all documents. If the cursor has been iterated, any previously iterated documents will not be included in results.

This method requires driver version >= 1.1.0.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var cursor *mongo.Cursor

	var results []bson.M
	if err := cursor.All(context.TODO(), &results); err != nil {
		log.Fatal(err)
	}
	fmt.Println(results)
}

Output:

func (*Cursor) Close 

func (c *Cursor) Close(ctx context.Context) error

Close closes this cursor. Next and TryNext must not be called after Close has been called. Close is idempotent. After the first call, any subsequent calls will not change the state.

func (*Cursor) Decode 

func (c *Cursor) Decode(val interface{}) error

Decode will unmarshal the current document into val and return any errors from the unmarshalling process without any modification. If val is nil or is a typed nil, an error will be returned.

func (*Cursor) Err 

func (c *Cursor) Err() error

Err returns the last error seen by the Cursor, or nil if no error has occurred.

func (*Cursor) ID 

func (c *Cursor) ID() int64

ID returns the ID of this cursor, or 0 if the cursor has been closed or exhausted.

func (*Cursor) Next 

func (c *Cursor) Next(ctx context.Context) bool

Next gets the next document for this cursor. It returns true if there were no errors and the cursor has not been exhausted.

Next blocks until a document is available, an error occurs, or ctx expires. If ctx expires, the error will be set to ctx.Err(). In an error case, Next will return false.

If Next returns false, subsequent calls will also return false.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var cursor *mongo.Cursor
	defer cursor.Close(context.TODO())

	// Iterate the cursor and print out each document until the cursor is exhausted or there is an error getting the
	// next document.
	for cursor.Next(context.TODO()) {
		// A new result variable should be declared for each document.
		var result bson.M
		if err := cursor.Decode(&result); err != nil {
			log.Fatal(err)
		}
		fmt.Println(result)
	}
	if err := cursor.Err(); err != nil {
		log.Fatal(err)
	}
}

Output:

func (*Cursor) TryNext 

func (c *Cursor) TryNext(ctx context.Context) bool

TryNext attempts to get the next document for this cursor. It returns true if there were no errors and the next document is available. This is only recommended for use with tailable cursors as a non-blocking alternative to Next. See https://docs.mongodb.com/manual/core/tailable-cursors/ for more information about tailable cursors.

TryNext returns false if the cursor is exhausted, an error occurs when getting results from the server, the next document is not yet available, or ctx expires. If ctx expires, the error will be set to ctx.Err().

If TryNext returns false and an error occurred or the cursor has been exhausted (i.e. c.Err() != nil || c.ID() == 0), subsequent attempts will also return false. Otherwise, it is safe to call TryNext again until a document is available.

This method requires driver version >= 1.2.0.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var cursor *mongo.Cursor
	defer cursor.Close(context.TODO())

	// Iterate the cursor and print out each document until the cursor is exhausted or there is an error getting the
	// next document.
	for {
		if cursor.TryNext(context.TODO()) {
			// A new result variable should be declared for each document.
			var result bson.M
			if err := cursor.Decode(&result); err != nil {
				log.Fatal(err)
			}
			fmt.Println(result)
			continue
		}

		// If TryNext returns false, the next document is not yet available, the cursor was exhausted and was closed, or
		// an error occured. TryNext should only be called again for the empty batch case.
		if err := cursor.Err(); err != nil {
			log.Fatal(err)
		}
		if cursor.ID() == 0 {
			break
		}
	}
}

Output:

type Database 

type Database struct {
	// contains filtered or unexported fields
}

Database is a handle to a MongoDB database. It is safe for concurrent use by multiple goroutines.

func (*Database) Aggregate 

func (db *Database) Aggregate(ctx context.Context, pipeline interface{},
	opts ...*options.AggregateOptions) (*Cursor, error)

Aggregate executes an aggregate command the database. This requires MongoDB version >= 3.6 and driver version >= 1.1.0.

The pipeline parameter must be a slice of documents, each representing an aggregation stage. The pipeline cannot be nil but can be empty. The stage documents must all be non-nil. For a pipeline of bson.D documents, the mongo.Pipeline type can be used. See https://docs.mongodb.com/manual/reference/operator/aggregation-pipeline/#db-aggregate-stages for a list of valid stages in database-level aggregations.

The opts parameter can be used to specify options for this operation (see the options.AggregateOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/aggregate/.

func (*Database) Client 

func (db *Database) Client() *Client

Client returns the Client the Database was created from.

func (*Database) Collection 

func (db *Database) Collection(name string, opts ...*options.CollectionOptions) *Collection

Collection gets a handle for a collection with the given name configured with the given CollectionOptions.

func (*Database) Drop 

func (db *Database) Drop(ctx context.Context) error

Drop drops the database on the server. This method ignores "namespace not found" errors so it is safe to drop a database that does not exist on the server.

func (*Database) ListCollectionNames 

func (db *Database) ListCollectionNames(ctx context.Context, filter interface{}, opts ...*options.ListCollectionsOptions) ([]string, error)

ListCollectionNames executes a listCollections command and returns a slice containing the names of the collections in the database. This method requires driver version >= 1.1.0.

The filter parameter must be a document containing query operators and can be used to select which collections are included in the result. It cannot be nil. An empty document (e.g. bson.D{}) should be used to include all collections.

The opts parameter can be used to specify options for the operation (see the options.ListCollectionsOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/listCollections/.

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
)

func main() {
	var db *mongo.Database

	// use a filter to only select capped collections
	result, err := db.ListCollectionNames(context.TODO(), bson.D{{"options.capped", true}})
	if err != nil {
		log.Fatal(err)
	}

	for _, coll := range result {
		fmt.Println(coll)
	}
}

Output:

func (*Database) ListCollections 

func (db *Database) ListCollections(ctx context.Context, filter interface{}, opts ...*options.ListCollectionsOptions) (*Cursor, error)

ListCollections executes a listCollections command and returns a cursor over the collections in the database.

The filter parameter must be a document containing query operators and can be used to select which collections are included in the result. It cannot be nil. An empty document (e.g. bson.D{}) should be used to include all collections.

The opts parameter can be used to specify options for the operation (see the options.ListCollectionsOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/listCollections/.

func (*Database) Name 

func (db *Database) Name() string

Name returns the name of the database.

func (*Database) ReadConcern 

func (db *Database) ReadConcern() *readconcern.ReadConcern

ReadConcern returns the read concern used to configure the Database object.

func (*Database) ReadPreference 

func (db *Database) ReadPreference() *readpref.ReadPref

ReadPreference returns the read preference used to configure the Database object.

func (*Database) RunCommand 

func (db *Database) RunCommand(ctx context.Context, runCommand interface{}, opts ...*options.RunCmdOptions) *SingleResult

RunCommand executes the given command against the database.

The runCommand parameter must be a document for the command to be executed. It cannot be nil. This must be an order-preserving type such as bson.D. Map types such as bson.M are not valid. If the command document contains a session ID or any transaction-specific fields, the behavior is undefined.

The opts parameter can be used to specify options for this operation (see the options.RunCmdOptions documentation).

Example 
package main

import (
	"context"
	"fmt"
	"log"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
	"go.mongodb.org/mongo-driver/mongo/readpref"
)

func main() {
	var db *mongo.Database

	// run an explain command to see the query plan for when a "find" is executed on collection "bar"
	// specify the ReadPreference option to explicitly set the read preference to primary
	findCmd := bson.D{{"find", "bar"}}
	command := bson.D{{"explain", findCmd}}
	opts := options.RunCmd().SetReadPreference(readpref.Primary())
	var result bson.M
	if err := db.RunCommand(context.TODO(), command, opts).Decode(&result); err != nil {
		log.Fatal(err)
	}
	fmt.Println(result)
}

Output:

func (*Database) RunCommandCursor 

func (db *Database) RunCommandCursor(ctx context.Context, runCommand interface{}, opts ...*options.RunCmdOptions) (*Cursor, error)

RunCommandCursor executes the given command against the database and parses the response as a cursor. If the command being executed does not return a cursor (e.g. insert), the command will be executed on the server and an error will be returned because the server response cannot be parsed as a cursor.

The runCommand parameter must be a document for the command to be executed. It cannot be nil. This must be an order-preserving type such as bson.D. Map types such as bson.M are not valid. If the command document contains a session ID or any transaction-specific fields, the behavior is undefined.

The opts parameter can be used to specify options for this operation (see the options.RunCmdOptions documentation).

func (*Database) Watch 

func (db *Database) Watch(ctx context.Context, pipeline interface{},
	opts ...*options.ChangeStreamOptions) (*ChangeStream, error)

Watch returns a change stream for all changes to the corresponding database. See https://docs.mongodb.com/manual/changeStreams/ for more information about change streams.

The Database must be configured with read concern majority or no read concern for a change stream to be created successfully.

The pipeline parameter must be a slice of documents, each representing a pipeline stage. The pipeline cannot be nil but can be empty. The stage documents must all be non-nil. See https://docs.mongodb.com/manual/changeStreams/ for a list of pipeline stages that can be used with change streams. For a pipeline of bson.D documents, the mongo.Pipeline{} type can be used.

The opts parameter can be used to specify options for change stream creation (see the options.ChangeStreamOptions documentation).

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var db *mongo.Database

	// specify a pipeline that will only match "insert" events
	// specify the MaxAwaitTimeOption to have each attempt wait two seconds for new documents
	matchStage := bson.D{{"$match", bson.D{{"operationType", "insert"}}}}
	opts := options.ChangeStream().SetMaxAwaitTime(2 * time.Second)
	changeStream, err := db.Watch(context.TODO(), mongo.Pipeline{matchStage}, opts)
	if err != nil {
		log.Fatal(err)
	}

	// print out all change stream events in the order they're received
	// see the mongo.ChangeStream documentation for more examples of using change streams
	for changeStream.Next(context.TODO()) {
		fmt.Println(changeStream.Current)
	}
}

Output:

func (*Database) WriteConcern 

func (db *Database) WriteConcern() *writeconcern.WriteConcern

WriteConcern returns the write concern used to configure the Database object.

type DatabaseSpecification 

type DatabaseSpecification struct {
	Name       string // The name of the database.
	SizeOnDisk int64  // The total size of the database files on disk in bytes.
	Empty      bool   // Specfies whether or not the database is empty.
}

DatabaseSpecification contains information for a database. This type is returned as part of ListDatabasesResult.

type DeleteManyModel 

type DeleteManyModel struct {
	Filter    interface{}
	Collation *options.Collation
}

DeleteManyModel is used to delete multiple documents in a BulkWrite operation.

func NewDeleteManyModel 

func NewDeleteManyModel() *DeleteManyModel

NewDeleteManyModel creates a new DeleteManyModel.

func (*DeleteManyModel) SetCollation 

func (dmm *DeleteManyModel) SetCollation(collation *options.Collation) *DeleteManyModel

SetCollation specifies a collation to use for string comparisons. The default is nil, meaning no collation will be used.

func (*DeleteManyModel) SetFilter 

func (dmm *DeleteManyModel) SetFilter(filter interface{}) *DeleteManyModel

SetFilter specifies a filter to use to select documents to delete. The filter must be a document containing query operators. It cannot be nil.

type DeleteOneModel 

type DeleteOneModel struct {
	Filter    interface{}
	Collation *options.Collation
}

DeleteOneModel is used to delete at most one document in a BulkWriteOperation.

func NewDeleteOneModel 

func NewDeleteOneModel() *DeleteOneModel

NewDeleteOneModel creates a new DeleteOneModel.

func (*DeleteOneModel) SetCollation 

func (dom *DeleteOneModel) SetCollation(collation *options.Collation) *DeleteOneModel

SetCollation specifies a collation to use for string comparisons. The default is nil, meaning no collation will be used.

func (*DeleteOneModel) SetFilter 

func (dom *DeleteOneModel) SetFilter(filter interface{}) *DeleteOneModel

SetFilter specifies a filter to use to select the document to delete. The filter must be a document containing query operators. It cannot be nil. If the filter matches multiple documents, one will be selected from the matching documents.

type DeleteResult 

type DeleteResult struct {
	DeletedCount int64 `bson:"n"` // The number of documents deleted.
}

DeleteResult is the result type returned by DeleteOne and DeleteMany operations.

type Dialer 

type Dialer interface {
	DialContext(ctx context.Context, network, address string) (net.Conn, error)
}

Dialer is used to make network connections.

type EncryptionKeyVaultError 

type EncryptionKeyVaultError struct {
	Wrapped error
}

EncryptionKeyVaultError represents an error while communicating with the key vault collection during client-side encryption.

func (EncryptionKeyVaultError) Error 

func (ekve EncryptionKeyVaultError) Error() string

Error implements the error interface.

type IndexModel 

type IndexModel struct {
	// A document describing which keys should be used for the index. It cannot be nil. See
	// https://docs.mongodb.com/manual/indexes/#indexes for examples of valid documents.
	Keys interface{}

	// The options to use to create the index.
	Options *options.IndexOptions
}

IndexModel represents a new index to be created.

type IndexOptionsBuilder 

type IndexOptionsBuilder struct {
	// contains filtered or unexported fields
}

IndexOptionsBuilder is deprecated and unused. Use mongo/options.IndexOptions instead.

func NewIndexOptionsBuilder 

func NewIndexOptionsBuilder() *IndexOptionsBuilder

NewIndexOptionsBuilder is deprecated.

func (*IndexOptionsBuilder) Background 

func (iob *IndexOptionsBuilder) Background(background bool) *IndexOptionsBuilder

Background is deprecated.

func (*IndexOptionsBuilder) Bits 

func (iob *IndexOptionsBuilder) Bits(bits int32) *IndexOptionsBuilder

Bits is deprecated.

func (*IndexOptionsBuilder) BucketSize 

func (iob *IndexOptionsBuilder) BucketSize(bucketSize int32) *IndexOptionsBuilder

BucketSize is deprecated.

func (*IndexOptionsBuilder) Build 

func (iob *IndexOptionsBuilder) Build() bson.D

Build is deprecated.

func (*IndexOptionsBuilder) Collation 

func (iob *IndexOptionsBuilder) Collation(collation interface{}) *IndexOptionsBuilder

Collation is deprecated.

func (*IndexOptionsBuilder) DefaultLanguage 

func (iob *IndexOptionsBuilder) DefaultLanguage(defaultLanguage string) *IndexOptionsBuilder

DefaultLanguage is deprecated.

func (*IndexOptionsBuilder) ExpireAfterSeconds 

func (iob *IndexOptionsBuilder) ExpireAfterSeconds(expireAfterSeconds int32) *IndexOptionsBuilder

ExpireAfterSeconds is deprecated.

func (*IndexOptionsBuilder) LanguageOverride 

func (iob *IndexOptionsBuilder) LanguageOverride(languageOverride string) *IndexOptionsBuilder

LanguageOverride is deprecated.

func (*IndexOptionsBuilder) Max 

func (iob *IndexOptionsBuilder) Max(max float64) *IndexOptionsBuilder

Max is deprecated.

func (*IndexOptionsBuilder) Min 

func (iob *IndexOptionsBuilder) Min(min float64) *IndexOptionsBuilder

Min is deprecated.

func (*IndexOptionsBuilder) Name 

func (iob *IndexOptionsBuilder) Name(name string) *IndexOptionsBuilder

Name is deprecated.

func (*IndexOptionsBuilder) PartialFilterExpression 

func (iob *IndexOptionsBuilder) PartialFilterExpression(partialFilterExpression interface{}) *IndexOptionsBuilder

PartialFilterExpression is deprecated.

func (*IndexOptionsBuilder) Sparse 

func (iob *IndexOptionsBuilder) Sparse(sparse bool) *IndexOptionsBuilder

Sparse is deprecated.

func (*IndexOptionsBuilder) SphereVersion 

func (iob *IndexOptionsBuilder) SphereVersion(sphereVersion int32) *IndexOptionsBuilder

SphereVersion is deprecated.

func (*IndexOptionsBuilder) StorageEngine 

func (iob *IndexOptionsBuilder) StorageEngine(storageEngine interface{}) *IndexOptionsBuilder

StorageEngine is deprecated.

func (*IndexOptionsBuilder) TextVersion 

func (iob *IndexOptionsBuilder) TextVersion(textVersion int32) *IndexOptionsBuilder

TextVersion is deprecated.

func (*IndexOptionsBuilder) Unique 

func (iob *IndexOptionsBuilder) Unique(unique bool) *IndexOptionsBuilder

Unique is deprecated.

func (*IndexOptionsBuilder) Version 

func (iob *IndexOptionsBuilder) Version(version int32) *IndexOptionsBuilder

Version is deprecated.

func (*IndexOptionsBuilder) Weights 

func (iob *IndexOptionsBuilder) Weights(weights interface{}) *IndexOptionsBuilder

Weights is deprecated.

type IndexView 

type IndexView struct {
	// contains filtered or unexported fields
}

IndexView is a type that can be used to create, drop, and list indexes on a collection. An IndexView for a collection can be created by a call to Collection.Indexes().

func (IndexView) CreateMany 

func (iv IndexView) CreateMany(ctx context.Context, models []IndexModel, opts ...*options.CreateIndexesOptions) ([]string, error)

CreateMany executes a createIndexes command to create multiple indexes on the collection and returns the names of the new indexes.

For each IndexModel in the models parameter, the index name can be specified via the Options field. If a name is not given, it will be generated from the Keys document.

The opts parameter can be used to specify options for this operation (see the options.CreateIndexesOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/createIndexes/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var indexView *mongo.IndexView

	// Create two indexes: {name: 1, email: 1} and {name: 1, age: 1}
	// For the first index, specify no options. The name will be generated as "name_1_email_1" by the driver.
	// For the second index, specify the Name option to explicitly set the name to "nameAge".
	models := []mongo.IndexModel{
		{
			Keys: bson.D{{"name", 1}, {"email", 1}},
		},
		{
			Keys:    bson.D{{"name", 1}, {"age", 1}},
			Options: options.Index().SetName("nameAge"),
		},
	}

	// Specify the MaxTime option to limit the amount of time the operation can run on the server
	opts := options.CreateIndexes().SetMaxTime(2 * time.Second)
	names, err := indexView.CreateMany(context.TODO(), models, opts)
	if err != nil {
		log.Fatal(err)
	}

	fmt.Printf("created indexes %v\n", names)
}

Output:

func (IndexView) CreateOne 

func (iv IndexView) CreateOne(ctx context.Context, model IndexModel, opts ...*options.CreateIndexesOptions) (string, error)

CreateOne executes a createIndexes command to create an index on the collection and returns the name of the new index. See the IndexView.CreateMany documentation for more information and an example.

func (IndexView) DropAll 

func (iv IndexView) DropAll(ctx context.Context, opts ...*options.DropIndexesOptions) (bson.Raw, error)

DropAll executes a dropIndexes operation to drop all indexes on the collection. If the operation succeeds, this returns a BSON document in the form {nIndexesWas: <int32>}. The "nIndexesWas" field in the response contains the number of indexes that existed prior to the drop.

The opts parameter can be used to specify options for this operation (see the options.DropIndexesOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/dropIndexes/.

func (IndexView) DropOne 

func (iv IndexView) DropOne(ctx context.Context, name string, opts ...*options.DropIndexesOptions) (bson.Raw, error)

DropOne executes a dropIndexes operation to drop an index on the collection. If the operation succeeds, this returns a BSON document in the form {nIndexesWas: <int32>}. The "nIndexesWas" field in the response contains the number of indexes that existed prior to the drop.

The name parameter should be the name of the index to drop. If the name is "*", ErrMultipleIndexDrop will be returned without running the command because doing so would drop all indexes.

The opts parameter can be used to specify options for this operation (see the options.DropIndexesOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/dropIndexes/.

func (IndexView) List 

func (iv IndexView) List(ctx context.Context, opts ...*options.ListIndexesOptions) (*Cursor, error)

List executes a listIndexes command and returns a cursor over the indexes in the collection.

The opts parameter can be used to specify options for this operation (see the options.ListIndexesOptions documentation).

For more information about the command, see https://docs.mongodb.com/manual/reference/command/listIndexes/.

Example 
package main

import (
	"context"
	"fmt"
	"log"
	"time"

	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo"
	"go.mongodb.org/mongo-driver/mongo/options"
)

func main() {
	var indexView *mongo.IndexView

	// Specify the MaxTime option to limit the amount of time the operation can run on the server
	opts := options.ListIndexes().SetMaxTime(2 * time.Second)
	cursor, err := indexView.List(context.TODO(), opts)
	if err != nil {
		log.Fatal(err)
	}

	// Get a slice of all indexes returned and print them out.
	var results []bson.M
	if err = cursor.All(context.TODO(), &results); err != nil {
		log.Fatal(err)
	}
	fmt.Println(results)
}

Output:

type InsertManyResult 

type InsertManyResult struct {
	// The _id values of the inserted documents. Values generated by the driver will be of type primitive.ObjectID.
	InsertedIDs []interface{}
}

InsertManyResult is a result type returned by an InsertMany operation.

type InsertOneModel 

type InsertOneModel struct {
	Document interface{}
}

InsertOneModel is used to insert a single document in a BulkWrite operation.

func NewInsertOneModel 

func NewInsertOneModel() *InsertOneModel

NewInsertOneModel creates a new InsertOneModel.

func (*InsertOneModel) SetDocument 

func (iom *InsertOneModel) SetDocument(doc interface{}) *InsertOneModel

SetDocument specifies the document to be inserted. The document cannot be nil. If it does not have an _id field when transformed into BSON, one will be added automatically to the marshalled document. The original document will not be modified.

type InsertOneResult 

type InsertOneResult struct {
	// The _id of the inserted document. A value generated by the driver will be of type primitive.ObjectID.
	InsertedID interface{}
}

InsertOneResult is the result type returned by an InsertOne operation.

type ListDatabasesResult 

type ListDatabasesResult struct {
	// A slice containing one DatabaseSpecification for each database matched by the operation's filter.
	Databases []DatabaseSpecification

	// The total size of the database files of the returned databases in bytes.
	// This will be the sum of the SizeOnDisk field for each specification in Databases.
	TotalSize int64
}

ListDatabasesResult is a result of a ListDatabases operation.

type MarshalError 

type MarshalError struct {
	Value interface{}
	Err   error
}

MarshalError is returned when attempting to transform a value into a document results in an error.

func (MarshalError) Error 

func (me MarshalError) Error() string

Error implements the error interface.

type MongocryptError 

type MongocryptError struct {
	Code    int32
	Message string
}

MongocryptError represents an libmongocrypt error during client-side encryption.

func (MongocryptError) Error 

func (m MongocryptError) Error() string

Error implements the error interface.

type MongocryptdError 

type MongocryptdError struct {
	Wrapped error
}

MongocryptdError represents an error while communicating with mongocryptd during client-side encryption.

func (MongocryptdError) Error 

func (e MongocryptdError) Error() string

Error implements the error interface.

type Pipeline 

type Pipeline []bson.D

Pipeline is a type that makes creating aggregation pipelines easier. It is a helper and is intended for serializing to BSON.

Example usage: 

mongo.Pipeline{
	{{"$group", bson.D{{"_id", "$state"}, {"totalPop", bson.D{{"$sum", "$pop"}}}}}},
	{{"$match", bson.D{{"totalPop", bson.D{{"$gte", 10*1000*1000}}}}}},
}

type ReplaceOneModel 

type ReplaceOneModel struct {
	Collation   *options.Collation
	Upsert      *bool
	Filter      interface{}
	Replacement interface{}
}

ReplaceOneModel is used to replace at most one document in a BulkWrite operation.

func NewReplaceOneModel 

func NewReplaceOneModel() *ReplaceOneModel

NewReplaceOneModel creates a new ReplaceOneModel.

func (*ReplaceOneModel) SetCollation 

func (rom *ReplaceOneModel) SetCollation(collation *options.Collation) *ReplaceOneModel

SetCollation specifies a collation to use for string comparisons. The default is nil, meaning no collation will be used.

func (*ReplaceOneModel) SetFilter 

func (rom *ReplaceOneModel) SetFilter(filter interface{}) *ReplaceOneModel

SetFilter specifies a filter to use to select the document to replace. The filter must be a document containing query operators. It cannot be nil. If the filter matches multiple documents, one will be selected from the matching documents.

func (*ReplaceOneModel) SetReplacement 

func (rom *ReplaceOneModel) SetReplacement(rep interface{}) *ReplaceOneModel

SetReplacement specifies a document that will be used to replace the selected document. It cannot be nil and cannot contain any update operators (https://docs.mongodb.com/manual/reference/operator/update/).

func (*ReplaceOneModel) SetUpsert 

func (rom *ReplaceOneModel) SetUpsert(upsert bool) *ReplaceOneModel

SetUpsert specifies whether or not the replacement document should be inserted if no document matching the filter is found. If an upsert is performed, the _id of the upserted document can be retrieved from the UpsertedIDs field of the BulkWriteResult.

type Session 

type Session interface {
	StartTransaction(...*options.TransactionOptions) error
	AbortTransaction(context.Context) error
	CommitTransaction(context.Context) error
	WithTransaction(ctx context.Context, fn func(sessCtx SessionContext) (interface{}, error),
		opts ...*options.TransactionOptions) (interface{}, error)
	ClusterTime() bson.Raw
	OperationTime() *primitive.Timestamp
	Client() *Client
	EndSession(context.Context)

	AdvanceClusterTime(bson.Raw) error
	AdvanceOperationTime(*primitive.Timestamp) error
	// contains filtered or unexported methods
}

Session is an interface that represents a MongoDB logical session. Sessions can be used to enable causal consistency for a group of operations or to execute operations in an ACID transaction. A new Session can be created from a Client instance. A Session created from a Client must only be used to execute operations using that Client or a Database or Collection created from that Client. Custom implementations of this interface should not be used in production. For more information about sessions, and their use cases, see https://docs.mongodb.com/manual/reference/server-sessions/, https://docs.mongodb.com/manual/core/read-isolation-consistency-recency/#causal-consistency, and https://docs.mongodb.com/manual/core/transactions/.

StartTransaction starts a new transaction, configured with the given options, on this session. This method will return an error if there is already a transaction in-progress for this session.

CommitTransaction commits the active transaction for this session. This method will return an error if there is no active transaction for this session or the transaction has been aborted.

AbortTransaction aborts the active transaction for this session. This method will return an error if there is no active transaction for this session or the transaction has been committed or aborted.

WithTransaction starts a transaction on this session and runs the fn callback. Errors with the TransientTransactionError and UnknownTransactionCommitResult labels are retried for up to 120 seconds. Inside the callback, sessCtx must be used as the Context parameter for any operations that should be part of the transaction. If the ctx parameter already has a Session attached to it, it will be replaced by this session. The fn callback may be run multiple times during WithTransaction due to retry attempts, so it must be idempotent. Non-retryable operation errors or any operation errors that occur after the timeout expires will be returned without retrying. For a usage example, see the Client.StartSession method documentation.

ClusterTime, OperationTime, and Client return the session's current operation time, the session's current cluster time, and the Client associated with the session, respectively.

EndSession method should abort any existing transactions and close the session.

AdvanceClusterTime and AdvanceOperationTime are for internal use only and must not be called.

type SessionContext 

type SessionContext interface {
	context.Context
	Session
}

SessionContext combines the context.Context and mongo.Session interfaces. It should be used as the Context arguments to operations that should be executed in a session. This type is not goroutine safe and must not be used concurrently by multiple goroutines.

type SingleResult 

type SingleResult struct {
	// contains filtered or unexported fields
}

SingleResult represents a single document returned from an operation. If the operation resulted in an error, all SingleResult methods will return that error. If the operation did not return any documents, all SingleResult methods will return ErrNoDocuments.

func (*SingleResult) Decode 

func (sr *SingleResult) Decode(v interface{}) error

Decode will unmarshal the document represented by this SingleResult into v. If there was an error from the operation that created this SingleResult, that error will be returned. If the operation returned no documents, DecodeBytes will return ErrNoDocuments.

If the operation was successful and returned a document, Decode will return any errors from the unmarshalling process without any modification. If v is nil or is a typed nil, an error will be returned.

func (*SingleResult) DecodeBytes 

func (sr *SingleResult) DecodeBytes() (bson.Raw, error)

DecodeBytes will return the document represented by this SingleResult as a bson.Raw. If there was an error from the operation that created this SingleResult, both the result and that error will be returned. If the operation returned no documents, this will return (nil, ErrNoDocuments).

func (*SingleResult) Err 

func (sr *SingleResult) Err() error

Err returns the error from the operation that created this SingleResult. If the operation was successful but did not return any documents, Err will return ErrNoDocuments. If the operation was successful and returned a document, Err will return nil.

type StreamType 

type StreamType uint8

StreamType represents the cluster type against which a ChangeStream was created. 

const (
	CollectionStream StreamType = iota
	DatabaseStream
	ClientStream
)

These constants represent valid change stream types. A change stream can be initialized over a collection, all collections in a database, or over a cluster.

type UpdateManyModel 

type UpdateManyModel struct {
	Collation    *options.Collation
	Upsert       *bool
	Filter       interface{}
	Update       interface{}
	ArrayFilters *options.ArrayFilters
}

UpdateManyModel is used to update multiple documents in a BulkWrite operation.

func NewUpdateManyModel 

func NewUpdateManyModel() *UpdateManyModel

NewUpdateManyModel creates a new UpdateManyModel.

func (*UpdateManyModel) SetArrayFilters 

func (umm *UpdateManyModel) SetArrayFilters(filters options.ArrayFilters) *UpdateManyModel

SetArrayFilters specifies a set of filters to determine which elements should be modified when updating an array field.

func (*UpdateManyModel) SetCollation 

func (umm *UpdateManyModel) SetCollation(collation *options.Collation) *UpdateManyModel

SetCollation specifies a collation to use for string comparisons. The default is nil, meaning no collation will be used.

func (*UpdateManyModel) SetFilter 

func (umm *UpdateManyModel) SetFilter(filter interface{}) *UpdateManyModel

SetFilter specifies a filter to use to select documents to update. The filter must be a document containing query operators. It cannot be nil.

func (*UpdateManyModel) SetUpdate 

func (umm *UpdateManyModel) SetUpdate(update interface{}) *UpdateManyModel

SetUpdate specifies the modifications to be made to the selected documents. The value must be a document containing update operators (https://docs.mongodb.com/manual/reference/operator/update/). It cannot be nil or empty.

func (*UpdateManyModel) SetUpsert 

func (umm *UpdateManyModel) SetUpsert(upsert bool) *UpdateManyModel

SetUpsert specifies whether or not a new document should be inserted if no document matching the filter is found. If an upsert is performed, the _id of the upserted document can be retrieved from the UpsertedIDs field of the BulkWriteResult.

type UpdateOneModel 

type UpdateOneModel struct {
	Collation    *options.Collation
	Upsert       *bool
	Filter       interface{}
	Update       interface{}
	ArrayFilters *options.ArrayFilters
}

UpdateOneModel is used to update at most one document in a BulkWrite operation.

func NewUpdateOneModel 

func NewUpdateOneModel() *UpdateOneModel

NewUpdateOneModel creates a new UpdateOneModel.

func (*UpdateOneModel) SetArrayFilters 

func (uom *UpdateOneModel) SetArrayFilters(filters options.ArrayFilters) *UpdateOneModel

SetArrayFilters specifies a set of filters to determine which elements should be modified when updating an array field.

func (*UpdateOneModel) SetCollation 

func (uom *UpdateOneModel) SetCollation(collation *options.Collation) *UpdateOneModel

SetCollation specifies a collation to use for string comparisons. The default is nil, meaning no collation will be used.

func (*UpdateOneModel) SetFilter 

func (uom *UpdateOneModel) SetFilter(filter interface{}) *UpdateOneModel

SetFilter specifies a filter to use to select the document to update. The filter must be a document containing query operators. It cannot be nil. If the filter matches multiple documents, one will be selected from the matching documents.

func (*UpdateOneModel) SetUpdate 

func (uom *UpdateOneModel) SetUpdate(update interface{}) *UpdateOneModel

SetUpdate specifies the modifications to be made to the selected document. The value must be a document containing update operators (https://docs.mongodb.com/manual/reference/operator/update/). It cannot be nil or empty.

func (*UpdateOneModel) SetUpsert 

func (uom *UpdateOneModel) SetUpsert(upsert bool) *UpdateOneModel

SetUpsert specifies whether or not a new document should be inserted if no document matching the filter is found. If an upsert is performed, the _id of the upserted document can be retrieved from the UpsertedIDs field of the BulkWriteResult.

type UpdateResult 

type UpdateResult struct {
	MatchedCount  int64       // The number of documents matched by the filter.
	ModifiedCount int64       // The number of documents modified by the operation.
	UpsertedCount int64       // The number of documents upserted by the operation.
	UpsertedID    interface{} // The _id field of the upserted document, or nil if no upsert was done.
}

UpdateResult is the result type returned from UpdateOne, UpdateMany, and ReplaceOne operations.

func (*UpdateResult) UnmarshalBSON 

func (result *UpdateResult) UnmarshalBSON(b []byte) error

UnmarshalBSON implements the bson.Unmarshaler interface.

type WriteConcernError 

type WriteConcernError struct {
	Name    string
	Code    int
	Message string
	Details bson.Raw
}

WriteConcernError represents a write concern failure during execution of a write operation. This error type is only returned as part of a WriteException or a BulkWriteException.

func (WriteConcernError) Error 

func (wce WriteConcernError) Error() string

Error implements the error interface.

type WriteError 

type WriteError struct {
	// The index of the write in the slice passed to an InsertMany or BulkWrite operation that caused this error.
	Index int

	Code    int
	Message string
}

WriteError is an error that occurred during execution of a write operation. This error type is only returned as part of a WriteException or BulkWriteException.

func (WriteError) Error 

func (we WriteError) Error() string

type WriteErrors 

type WriteErrors []WriteError

WriteErrors is a group of write errors that occurred during execution of a write operation.

func (WriteErrors) Error 

func (we WriteErrors) Error() string

Error implements the error interface.

type WriteException 

type WriteException struct {
	// The write concern error that occurred, or nil if there was none.
	WriteConcernError *WriteConcernError

	// The write errors that occurred during operation execution.
	WriteErrors WriteErrors
}

WriteException is the error type returned by the InsertOne, DeleteOne, DeleteMany, UpdateOne, UpdateMany, and ReplaceOne operations.

func (WriteException) Error 

func (mwe WriteException) Error() string

Error implements the error interface.

type WriteModel 

type WriteModel interface {
	// contains filtered or unexported methods
}

WriteModel is an interface implemented by models that can be used in a BulkWrite operation. Each WriteModel represents a write.

This interface is implemented by InsertOneModel, DeleteOneModel, DeleteManyModel, ReplaceOneModel, UpdateOneModel, and UpdateManyModel. Custom implementations of this interface must not be used.

type XSession 

type XSession interface {
	ClientSession() *session.Client
	ID() bsonx.Doc
}

XSession is an unstable interface for internal use only. This interface is deprecated and is not part of the stability guarantee. It may be removed at any time.

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