spanner

package
v0.42.0 Latest Latest
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 Go to latest Published: Jul 18, 2019 License: Apache-2.0 Imports: 17 Imported by: 3

Documentation

Overview

Cloud Spanner is a managed, mission-critical, globally consistent and scalable relational database service.

Use of Context

The ctx passed to NewClient is used for authentication requests and for creating the underlying connection, but is not used for subsequent calls. Individual methods on the client use the ctx given to them.

To close the open connection, use the Close() method.

For information about setting deadlines, reusing contexts, and more please visit godoc.org/cloud.google.com/go.

Use the client at cloud.google.com/go/spanner in preference to this.

Index

Examples

Constants

This section is empty.

Variables

This section is empty.

Functions

func DatabasePath deprecated 

func DatabasePath(project, instance, database string) string

DatabasePath returns the path for the database resource.

Deprecated: Use 

fmt.Sprintf("projects/%s/instances/%s/databases/%s", project, instance, database)

instead.

func DefaultAuthScopes 

func DefaultAuthScopes() []string

DefaultAuthScopes reports the default set of authentication scopes to use with this package.

func SessionPath deprecated 

func SessionPath(project, instance, database, session string) string

SessionPath returns the path for the session resource.

Deprecated: Use 

fmt.Sprintf("projects/%s/instances/%s/databases/%s/sessions/%s", project, instance, database, session)

instead.

Types

type CallOptions 

type CallOptions struct {
	CreateSession       []gax.CallOption
	GetSession          []gax.CallOption
	ListSessions        []gax.CallOption
	DeleteSession       []gax.CallOption
	ExecuteSql          []gax.CallOption
	ExecuteStreamingSql []gax.CallOption
	ExecuteBatchDml     []gax.CallOption
	Read                []gax.CallOption
	StreamingRead       []gax.CallOption
	BeginTransaction    []gax.CallOption
	Commit              []gax.CallOption
	Rollback            []gax.CallOption
	PartitionQuery      []gax.CallOption
	PartitionRead       []gax.CallOption
}

CallOptions contains the retry settings for each method of Client.

type Client 

type Client struct {

	// The call options for this service.
	CallOptions *CallOptions
	// contains filtered or unexported fields
}

Client is a client for interacting with Cloud Spanner API.

Methods, except Close, may be called concurrently. However, fields must not be modified concurrently with method calls.

func NewClient 

func NewClient(ctx context.Context, opts ...option.ClientOption) (*Client, error)

NewClient creates a new spanner client.

Cloud Spanner API

The Cloud Spanner API can be used to manage sessions and execute transactions on data stored in Cloud Spanner databases.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use client.
	_ = c
}

Output:

func (*Client) BeginTransaction 

func (c *Client) BeginTransaction(ctx context.Context, req *spannerpb.BeginTransactionRequest, opts ...gax.CallOption) (*spannerpb.Transaction, error)

BeginTransaction begins a new transaction. This step can often be skipped: [Read][google.spanner.v1.Spanner.Read], [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] and [Commit][google.spanner.v1.Spanner.Commit] can begin a new transaction as a side-effect.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.BeginTransactionRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.BeginTransaction(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) Close 

func (c *Client) Close() error

Close closes the connection to the API service. The user should invoke this when the client is no longer required.

func (*Client) Commit 

func (c *Client) Commit(ctx context.Context, req *spannerpb.CommitRequest, opts ...gax.CallOption) (*spannerpb.CommitResponse, error)

Commit commits a transaction. The request includes the mutations to be applied to rows in the database.

Commit might return an ABORTED error. This can occur at any time; commonly, the cause is conflicts with concurrent transactions. However, it can also happen for a variety of other reasons. If Commit returns ABORTED, the caller should re-attempt the transaction from the beginning, re-using the same session.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.CommitRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.Commit(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) Connection 

func (c *Client) Connection() *grpc.ClientConn

Connection returns the client's connection to the API service.

func (*Client) CreateSession 

func (c *Client) CreateSession(ctx context.Context, req *spannerpb.CreateSessionRequest, opts ...gax.CallOption) (*spannerpb.Session, error)

CreateSession creates a new session. A session can be used to perform transactions that read and/or modify data in a Cloud Spanner database. Sessions are meant to be reused for many consecutive transactions.

Sessions can only execute one transaction at a time. To execute multiple concurrent read-write/write-only transactions, create multiple sessions. Note that standalone reads and queries use a transaction internally, and count toward the one transaction limit.

Cloud Spanner limits the number of sessions that can exist at any given time; thus, it is a good idea to delete idle and/or unneeded sessions. Aside from explicit deletes, Cloud Spanner can delete sessions for which no operations are sent for more than an hour. If a session is deleted, requests to it return NOT_FOUND.

Idle sessions can be kept alive by sending a trivial SQL query periodically, e.g., "SELECT 1".

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.CreateSessionRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.CreateSession(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) DeleteSession 

func (c *Client) DeleteSession(ctx context.Context, req *spannerpb.DeleteSessionRequest, opts ...gax.CallOption) error

DeleteSession ends a session, releasing server resources associated with it. This will asynchronously trigger cancellation of any operations that are running with this session.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.DeleteSessionRequest{
		// TODO: Fill request struct fields.
	}
	err = c.DeleteSession(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
}

Output:

func (*Client) ExecuteBatchDml added in v0.37.0 

func (c *Client) ExecuteBatchDml(ctx context.Context, req *spannerpb.ExecuteBatchDmlRequest, opts ...gax.CallOption) (*spannerpb.ExecuteBatchDmlResponse, error)

ExecuteBatchDml executes a batch of SQL DML statements. This method allows many statements to be run with lower latency than submitting them sequentially with [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql].

Statements are executed in order, sequentially. [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse] will contain a [ResultSet][google.spanner.v1.ResultSet] for each DML statement that has successfully executed. If a statement fails, its error status will be returned as part of the [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse]. Execution will stop at the first failed statement; the remaining statements will not run.

ExecuteBatchDml is expected to return an OK status with a response even if there was an error while processing one of the DML statements. Clients must inspect response.status to determine if there were any errors while processing the request.

See more details in [ExecuteBatchDmlRequest][Spanner.ExecuteBatchDmlRequest] and [ExecuteBatchDmlResponse][Spanner.ExecuteBatchDmlResponse].

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ExecuteBatchDmlRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.ExecuteBatchDml(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) ExecuteSql 

func (c *Client) ExecuteSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error)

ExecuteSql executes an SQL statement, returning all results in a single reply. This method cannot be used to return a result set larger than 10 MiB; if the query yields more data than that, the query fails with a FAILED_PRECONDITION error.

Operations inside read-write transactions might return ABORTED. If this occurs, the application should restart the transaction from the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.

Larger result sets can be fetched in streaming fashion by calling [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] instead.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ExecuteSqlRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.ExecuteSql(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) ExecuteStreamingSql 

func (c *Client) ExecuteStreamingSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (spannerpb.Spanner_ExecuteStreamingSqlClient, error)

ExecuteStreamingSql like [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], except returns the result set as a stream. Unlike [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql], there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.

Example 
package main

import (
	"context"
	"io"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ExecuteSqlRequest{
		// TODO: Fill request struct fields.
	}
	stream, err := c.ExecuteStreamingSql(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	for {
		resp, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			// TODO: handle error.
		}
		// TODO: Use resp.
		_ = resp
	}
}

Output:

func (*Client) GetSession 

func (c *Client) GetSession(ctx context.Context, req *spannerpb.GetSessionRequest, opts ...gax.CallOption) (*spannerpb.Session, error)

GetSession gets a session. Returns NOT_FOUND if the session does not exist. This is mainly useful for determining whether a session is still alive.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.GetSessionRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.GetSession(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) ListSessions added in v0.16.0 

func (c *Client) ListSessions(ctx context.Context, req *spannerpb.ListSessionsRequest, opts ...gax.CallOption) *SessionIterator

ListSessions lists all sessions in a given database.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"
	"google.golang.org/api/iterator"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ListSessionsRequest{
		// TODO: Fill request struct fields.
	}
	it := c.ListSessions(ctx, req)
	for {
		resp, err := it.Next()
		if err == iterator.Done {
			break
		}
		if err != nil {
			// TODO: Handle error.
		}
		// TODO: Use resp.
		_ = resp
	}
}

Output:

func (*Client) PartitionQuery added in v0.20.0 

func (c *Client) PartitionQuery(ctx context.Context, req *spannerpb.PartitionQueryRequest, opts ...gax.CallOption) (*spannerpb.PartitionResponse, error)

PartitionQuery creates a set of partition tokens that can be used to execute a query operation in parallel. Each of the returned partition tokens can be used by [ExecuteStreamingSql][google.spanner.v1.Spanner.ExecuteStreamingSql] to specify a subset of the query result to read. The same session and read-only transaction must be used by the PartitionQueryRequest used to create the partition tokens and the ExecuteSqlRequests that use the partition tokens.

Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it is not possible to resume the query, and the whole operation must be restarted from the beginning.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.PartitionQueryRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.PartitionQuery(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) PartitionRead added in v0.20.0 

func (c *Client) PartitionRead(ctx context.Context, req *spannerpb.PartitionReadRequest, opts ...gax.CallOption) (*spannerpb.PartitionResponse, error)

PartitionRead creates a set of partition tokens that can be used to execute a read operation in parallel. Each of the returned partition tokens can be used by [StreamingRead][google.spanner.v1.Spanner.StreamingRead] to specify a subset of the read result to read. The same session and read-only transaction must be used by the PartitionReadRequest used to create the partition tokens and the ReadRequests that use the partition tokens. There are no ordering guarantees on rows returned among the returned partition tokens, or even within each individual StreamingRead call issued with a partition_token.

Partition tokens become invalid when the session used to create them is deleted, is idle for too long, begins a new transaction, or becomes too old. When any of these happen, it is not possible to resume the read, and the whole operation must be restarted from the beginning.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.PartitionReadRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.PartitionRead(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) Read 

func (c *Client) Read(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error)

Read reads rows from the database using key lookups and scans, as a simple key/value style alternative to [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql]. This method cannot be used to return a result set larger than 10 MiB; if the read matches more data than that, the read fails with a FAILED_PRECONDITION error.

Reads inside read-write transactions might return ABORTED. If this occurs, the application should restart the transaction from the beginning. See [Transaction][google.spanner.v1.Transaction] for more details.

Larger result sets can be yielded in streaming fashion by calling [StreamingRead][google.spanner.v1.Spanner.StreamingRead] instead.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ReadRequest{
		// TODO: Fill request struct fields.
	}
	resp, err := c.Read(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	// TODO: Use resp.
	_ = resp
}

Output:

func (*Client) Rollback 

func (c *Client) Rollback(ctx context.Context, req *spannerpb.RollbackRequest, opts ...gax.CallOption) error

Rollback rolls back a transaction, releasing any locks it holds. It is a good idea to call this for any transaction that includes one or more [Read][google.spanner.v1.Spanner.Read] or [ExecuteSql][google.spanner.v1.Spanner.ExecuteSql] requests and ultimately decides not to commit.

Rollback returns OK if it successfully aborts the transaction, the transaction was already aborted, or the transaction is not found. Rollback never returns ABORTED.

Example 
package main

import (
	"context"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.RollbackRequest{
		// TODO: Fill request struct fields.
	}
	err = c.Rollback(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
}

Output:

func (*Client) SetGoogleClientInfo 

func (c *Client) SetGoogleClientInfo(keyval ...string)

SetGoogleClientInfo sets the name and version of the application in the `x-goog-api-client` header passed on each request. Intended for use by Google-written clients.

func (*Client) StreamingRead 

func (c *Client) StreamingRead(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (spannerpb.Spanner_StreamingReadClient, error)

StreamingRead like [Read][google.spanner.v1.Spanner.Read], except returns the result set as a stream. Unlike [Read][google.spanner.v1.Spanner.Read], there is no limit on the size of the returned result set. However, no individual row in the result set can exceed 100 MiB, and no column value can exceed 10 MiB.

Example 
package main

import (
	"context"
	"io"

	spanner "cloud.google.com/go/spanner/apiv1"

	spannerpb "google.golang.org/genproto/googleapis/spanner/v1"
)

func main() {
	ctx := context.Background()
	c, err := spanner.NewClient(ctx)
	if err != nil {
		// TODO: Handle error.
	}

	req := &spannerpb.ReadRequest{
		// TODO: Fill request struct fields.
	}
	stream, err := c.StreamingRead(ctx, req)
	if err != nil {
		// TODO: Handle error.
	}
	for {
		resp, err := stream.Recv()
		if err == io.EOF {
			break
		}
		if err != nil {
			// TODO: handle error.
		}
		// TODO: Use resp.
		_ = resp
	}
}

Output:

type SessionIterator added in v0.16.0 

type SessionIterator struct {

	// InternalFetch is for use by the Google Cloud Libraries only.
	// It is not part of the stable interface of this package.
	//
	// InternalFetch returns results from a single call to the underlying RPC.
	// The number of results is no greater than pageSize.
	// If there are no more results, nextPageToken is empty and err is nil.
	InternalFetch func(pageSize int, pageToken string) (results []*spannerpb.Session, nextPageToken string, err error)
	// contains filtered or unexported fields
}

SessionIterator manages a stream of *spannerpb.Session.

func (*SessionIterator) Next added in v0.16.0 

func (it *SessionIterator) Next() (*spannerpb.Session, error)

Next returns the next result. Its second return value is iterator.Done if there are no more results. Once Next returns Done, all subsequent calls will return Done.

func (*SessionIterator) PageInfo added in v0.16.0 

func (it *SessionIterator) PageInfo() *iterator.PageInfo

PageInfo supports pagination. See the google.golang.org/api/iterator package for details.

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