Documentation ¶
Overview ¶
Package spanner is an auto-generated package for the Cloud Spanner API.
Cloud Spanner is a managed, mission-critical, globally consistent and scalable relational database service.
General documentation ¶
For information that is relevant for all client libraries please reference https://pkg.go.dev/cloud.google.com/go#pkg-overview. Some information on this page includes:
- Authentication and Authorization
- Timeouts and Cancellation
- Testing against Client Libraries
- Debugging Client Libraries
- Inspecting errors
Example usage ¶
To get started with this package, create a client.
ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close()
The client will use your default application credentials. Clients should be reused instead of created as needed. The methods of Client are safe for concurrent use by multiple goroutines. The returned client must be Closed when it is done being used.
Using the Client ¶
The following is an example of making an API call with the newly created client.
ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.BatchCreateSessionsRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#BatchCreateSessionsRequest. } resp, err := c.BatchCreateSessions(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp
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.
Index ¶
- func DatabasePath(project, instance, database string) stringdeprecated
- func DefaultAuthScopes() []string
- func DefaultClientOptions() []option.ClientOption
- func SessionPath(project, instance, database, session string) stringdeprecated
- type CallOptions
- type Client
- func (c *Client) BatchCreateSessions(ctx context.Context, req *spannerpb.BatchCreateSessionsRequest, ...) (*spannerpb.BatchCreateSessionsResponse, error)
- func (c *Client) BatchWrite(ctx context.Context, req *spannerpb.BatchWriteRequest, opts ...gax.CallOption) (spannerpb.Spanner_BatchWriteClient, error)
- func (c *Client) BeginTransaction(ctx context.Context, req *spannerpb.BeginTransactionRequest, ...) (*spannerpb.Transaction, error)
- func (c *Client) Close() error
- func (c *Client) Commit(ctx context.Context, req *spannerpb.CommitRequest, opts ...gax.CallOption) (*spannerpb.CommitResponse, error)
- func (c *Client) Connection() *grpc.ClientConndeprecated
- func (c *Client) CreateSession(ctx context.Context, req *spannerpb.CreateSessionRequest, ...) (*spannerpb.Session, error)
- func (c *Client) DeleteSession(ctx context.Context, req *spannerpb.DeleteSessionRequest, ...) error
- func (c *Client) ExecuteBatchDml(ctx context.Context, req *spannerpb.ExecuteBatchDmlRequest, ...) (*spannerpb.ExecuteBatchDmlResponse, error)
- func (c *Client) ExecuteSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error)
- func (c *Client) ExecuteStreamingSql(ctx context.Context, req *spannerpb.ExecuteSqlRequest, opts ...gax.CallOption) (spannerpb.Spanner_ExecuteStreamingSqlClient, error)
- func (c *Client) GetSession(ctx context.Context, req *spannerpb.GetSessionRequest, opts ...gax.CallOption) (*spannerpb.Session, error)
- func (c *Client) ListSessions(ctx context.Context, req *spannerpb.ListSessionsRequest, ...) *SessionIterator
- func (c *Client) PartitionQuery(ctx context.Context, req *spannerpb.PartitionQueryRequest, ...) (*spannerpb.PartitionResponse, error)
- func (c *Client) PartitionRead(ctx context.Context, req *spannerpb.PartitionReadRequest, ...) (*spannerpb.PartitionResponse, error)
- func (c *Client) Read(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (*spannerpb.ResultSet, error)
- func (c *Client) Rollback(ctx context.Context, req *spannerpb.RollbackRequest, opts ...gax.CallOption) error
- func (c *Client) SetGoogleClientInfo(keyval ...string)
- func (c *Client) StreamingRead(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (spannerpb.Spanner_StreamingReadClient, error)
- type SessionIterator
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
func DatabasePath
deprecated
func DefaultAuthScopes ¶
func DefaultAuthScopes() []string
DefaultAuthScopes reports the default set of authentication scopes to use with this package.
func DefaultClientOptions ¶ added in v1.14.0
func DefaultClientOptions() []option.ClientOption
Returns the default client options used by the generated Spanner client.
This function is only intended for use by the client library, and may be removed at any time without any warning.
func SessionPath
deprecated
Types ¶
type CallOptions ¶
type CallOptions struct { CreateSession []gax.CallOption BatchCreateSessions []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 BatchWrite []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.
Cloud Spanner API ¶
The Cloud Spanner API can be used to manage sessions and execute transactions on data stored in Cloud Spanner databases.
func NewClient ¶
NewClient creates a new spanner client based on gRPC. The returned client must be Closed when it is done being used to clean up its underlying connections.
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() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() // TODO: Use client. _ = c }
Output:
func NewRESTClient ¶ added in v1.43.0
NewRESTClient creates a new spanner rest 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() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewRESTClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() // TODO: Use client. _ = c }
Output:
func (*Client) BatchCreateSessions ¶
func (c *Client) BatchCreateSessions(ctx context.Context, req *spannerpb.BatchCreateSessionsRequest, opts ...gax.CallOption) (*spannerpb.BatchCreateSessionsResponse, error)
BatchCreateSessions creates multiple new sessions.
This API can be used to initialize a session cache on the clients. See https://goo.gl/TgSFN2 (at https://goo.gl/TgSFN2) for best practices on session cache management.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.BatchCreateSessionsRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#BatchCreateSessionsRequest. } resp, err := c.BatchCreateSessions(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp }
Output:
func (*Client) BatchWrite ¶ added in v1.50.0
func (c *Client) BatchWrite(ctx context.Context, req *spannerpb.BatchWriteRequest, opts ...gax.CallOption) (spannerpb.Spanner_BatchWriteClient, error)
BatchWrite batches the supplied mutation groups in a collection of efficient transactions. All mutations in a group are committed atomically. However, mutations across groups can be committed non-atomically in an unspecified order and thus, they must be independent of each other. Partial failure is possible, i.e., some groups may have been committed successfully, while some may have failed. The results of individual batches are streamed into the response as the batches are applied.
BatchWrite requests are not replay protected, meaning that each mutation group may be applied more than once. Replays of non-idempotent mutations may have undesirable effects. For example, replays of an insert mutation may produce an already exists error or if you use generated or commit timestamp-based keys, it may result in additional rows being added to the mutation’s table. We recommend structuring your mutation groups to be idempotent to avoid this issue.
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, ExecuteSql and Commit can begin a new transaction as a side-effect.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.BeginTransactionRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#BeginTransactionRequest. } resp, err := c.BeginTransaction(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp }
Output:
func (*Client) Close ¶
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.
On very rare occasions, Commit might return UNKNOWN. This can happen, for example, if the client job experiences a 1+ hour networking failure. At that point, Cloud Spanner has lost track of the transaction outcome and we recommend that you perform another read from the database to see the state of things as they are now.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.CommitRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#CommitRequest. } resp, err := c.Commit(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp }
Output:
func (*Client) Connection
deprecated
func (c *Client) Connection() *grpc.ClientConn
Connection returns a connection to the API service.
Deprecated: Connections are now pooled so this method does not always return the same resource.
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.
Active sessions use additional server resources, so it is a good idea to delete idle and unneeded sessions. Aside from explicit deletes, Cloud Spanner may 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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.CreateSessionRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#CreateSessionRequest. } 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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.DeleteSessionRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#DeleteSessionRequest. } err = c.DeleteSession(ctx, req) if err != nil { // TODO: Handle error. } }
Output:
func (*Client) ExecuteBatchDml ¶
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.
Statements are executed in sequential order. A request can succeed even if a statement fails. The ExecuteBatchDmlResponse.status field in the response provides information about the statement that failed. Clients must inspect this field to determine whether an error occurred.
Execution stops after the first failed statement; the remaining statements are not executed.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.ExecuteBatchDmlRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#ExecuteBatchDmlRequest. } 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 for more details.
Larger result sets can be fetched in streaming fashion by calling ExecuteStreamingSql instead.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.ExecuteSqlRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#ExecuteSqlRequest. } 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, except returns the result set as a stream. Unlike 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.
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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.GetSessionRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#GetSessionRequest. } resp, err := c.GetSession(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp }
Output:
func (*Client) ListSessions ¶
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" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" "google.golang.org/api/iterator" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.ListSessionsRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#ListSessionsRequest. } 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 // If you need to access the underlying RPC response, // you can do so by casting the `Response` as below. // Otherwise, remove this line. Only populated after // first call to Next(). Not safe for concurrent access. _ = it.Response.(*spannerpb.ListSessionsResponse) } }
Output:
func (*Client) PartitionQuery ¶
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 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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.PartitionQueryRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#PartitionQueryRequest. } resp, err := c.PartitionQuery(ctx, req) if err != nil { // TODO: Handle error. } // TODO: Use resp. _ = resp }
Output:
func (*Client) PartitionRead ¶
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 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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.PartitionReadRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#PartitionReadRequest. } 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. 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 for more details.
Larger result sets can be yielded in streaming fashion by calling StreamingRead instead.
Example ¶
package main import ( "context" spanner "cloud.google.com/go/spanner/apiv1" spannerpb "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.ReadRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#ReadRequest. } 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 or 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 "cloud.google.com/go/spanner/apiv1/spannerpb" ) func main() { ctx := context.Background() // This snippet has been automatically generated and should be regarded as a code template only. // It will require modifications to work: // - It may require correct/in-range values for request initialization. // - It may require specifying regional endpoints when creating the service client as shown in: // https://pkg.go.dev/cloud.google.com/go#hdr-Client_Options c, err := spanner.NewClient(ctx) if err != nil { // TODO: Handle error. } defer c.Close() req := &spannerpb.RollbackRequest{ // TODO: Fill request struct fields. // See https://pkg.go.dev/cloud.google.com/go/spanner/apiv1/spannerpb#RollbackRequest. } err = c.Rollback(ctx, req) if err != nil { // TODO: Handle error. } }
Output:
func (*Client) SetGoogleClientInfo ¶
SetGoogleClientInfo sets the name and version of the application in the `x-goog-api-client` header passed on each request. Also passes any provided key-value pairs. Intended for use by Google-written clients.
Internal use only.
func (*Client) StreamingRead ¶
func (c *Client) StreamingRead(ctx context.Context, req *spannerpb.ReadRequest, opts ...gax.CallOption) (spannerpb.Spanner_StreamingReadClient, error)
StreamingRead like Read, except returns the result set as a stream. Unlike 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.
type SessionIterator ¶
type SessionIterator struct { // Response is the raw response for the current page. // It must be cast to the RPC response type. // Calling Next() or InternalFetch() updates this value. Response interface{} // 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 ¶
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 ¶
func (it *SessionIterator) PageInfo() *iterator.PageInfo
PageInfo supports pagination. See the google.golang.org/api/iterator package for details.