Class Transaction (6.16.0)

This type of transaction is the only way to write data into Cloud Spanner. These transactions rely on pessimistic locking and, if necessary, two-phase commit. Locking read-write transactions may abort, requiring the application to retry.

Calling either or signals that the transaction is finished and no further requests will be made. If for some reason you decide not to call one of the aformentioned methods, call to release the underlying Session.

Running a transaction via or automatically re-runs the transaction on ABORTED errors.

returns a plain Transaction object, requiring the user to retry manually.

Snapshot

Inheritance

Dml > Transaction

Package

@google-cloud/spanner

Examples


const {Spanner} = require('@google-cloud/spanner');
const spanner = new Spanner();

const instance = spanner.instance('my-instance');
const database = instance.database('my-database');

database.runTransaction(function(err, transaction) {
  // The `transaction` object is ready for use.
});

To manually control retrying the transaction, use the getTransaction method.


database.getTransaction(function(err, transaction) {
  // The `transaction` object is ready for use.
});

Constructors

(constructor)(session, options, queryOptions, requestOptions)

constructor(session: Session, options?: spannerClient.spanner.v1.TransactionOptions.ReadWrite, queryOptions?: IQueryOptions, requestOptions?: Pick<IRequestOptions, 'transactionTag'>);

Execute a DML statement and get the affected row count.

Transaction#runUpdate

Parameters
NameDescription
session Session
options ReadWrite
queryOptions IQueryOptions
requestOptions Pick<IRequestOptions, 'transactionTag'>
Example 

const query = 'UPDATE Account SET Balance = 1000 WHERE Key = 1';

transaction.runUpdate(query, (err, rowCount) => {
  if (err) {
    // Error handling omitted.
  }
});

Properties

commitTimestamp

commitTimestamp?: PreciseDate;

commitTimestampProto

commitTimestampProto?: spannerClient.protobuf.ITimestamp;

Methods

batchUpdate(queries, options)

batchUpdate(queries: Array<string | Statement>, options?: BatchUpdateOptions | CallOptions): Promise<BatchUpdateResponse>;

Execute a series of DML statements and get the affected row counts.

If any of the DML statements fail, the returned error will contain a list of results for all successfully executed statements.

Parameters
NameDescription
queries Array<string | Statement>
options BatchUpdateOptions | CallOptions

Options for configuring the request.

Returns
TypeDescription
Promise<BatchUpdateResponse>

{Promise

Examples 

const queries = [
  {
    sql: 'INSERT INTO MyTable (Key, Value) VALUES (@key, @value)',
    params: {key: 'my-key', value: 'my-value'},
  },
  {
    sql: 'UPDATE MyTable t SET t.Value = @value WHERE t.KEY = @key',
    params: {key: 'my-other-key', value: 'my-other-value'}
  }
];

transaction.batchUpdate(queries, (err, rowCounts, apiResponse) => {
  if (err) {
    // Error handling omitted.
  }
});

If the callback is omitted, we'll return a Promise.


const [rowCounts, apiResponse] = await transaction.batchUpdate(queries);

batchUpdate(queries, callback)

batchUpdate(queries: Array<string | Statement>, callback: BatchUpdateCallback): void;
Parameters
NameDescription
queries Array<string | Statement>
callback BatchUpdateCallback
Returns
TypeDescription
void

batchUpdate(queries, options, callback)

batchUpdate(queries: Array<string | Statement>, options: BatchUpdateOptions | CallOptions, callback: BatchUpdateCallback): void;
Parameters
NameDescription
queries Array<string | Statement>
options BatchUpdateOptions | CallOptions
callback BatchUpdateCallback
Returns
TypeDescription
void

commit(options)

commit(options?: CommitOptions | CallOptions): Promise<CommitResponse>;

Commit the transaction.

Wrapper around .

Parameter
NameDescription
options CommitOptions | CallOptions

Options for configuring the request.

Returns
TypeDescription
Promise<CommitResponse>

{Promise

Example 

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue a mutation (note that there is no callback passed to `insert`).
  transaction.insert('Singers', {
    SingerId: 'Id3b',
    Name: 'Joe West'
  });

  // Commit the transaction.
  transaction.commit(function(err, apiResponse) {
    if (!err) {
      // Get the commit timestamp on successful commits.
      const {commitTimestamp} = apiResponse;
    }
  });
});

commit(callback)

commit(callback: CommitCallback): void;
Parameter
NameDescription
callback CommitCallback
Returns
TypeDescription
void

commit(options, callback)

commit(options: CommitOptions | CallOptions, callback: CommitCallback): void;
Parameters
NameDescription
options CommitOptions | CallOptions
callback CommitCallback
Returns
TypeDescription
void

deleteRows(table, keys)

deleteRows(table: string, keys: Key[]): void;

Delete rows from a table.

Parameters
NameDescription
table string

The name of the table.

keys Key[]

The keys for the rows to delete. If using a composite key, provide an array within this array. See the example below.

Returns
TypeDescription
void
Examples 

const keys = ['Id1', 'Id2', 'Id3'];

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue this mutation until later calling `commit`.
  // Note that a callback is not passed to `deleteRows`.
  transaction.deleteRows('Singers', keys);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The rows were deleted successfully.
    }
  });
});

Provide an array for keys to delete rows with a composite key.


const keys = [
  [
    'Id1',
    'Name1'
  ],
  [
    'Id2',
    'Name2'
  ]
];

getUniqueKeys(rows)

static getUniqueKeys(rows: object[]): string[];

Takes a list of rows and returns all unique column names.

Parameter
NameDescription
rows object[]

The rows.

Returns
TypeDescription
string[]

{string[]}

insert(table, rows)

insert(table: string, rows: object | object[]): void;

Insert rows of data into this table.

Parameters
NameDescription
table string

The name of the table.

rows object | object[]

A map of names to values of data to insert into this table.

Returns
TypeDescription
void
Examples 

const row = {
  SingerId: 'Id3',
  Name: 'Eddie Wilson'
};

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue this mutation until later calling `commit`.
  // Note that a callback is not passed to `insert`.
  transaction.insert('Singers', row);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The row was inserted successfully.
    }
  });
});

Multiple rows can be inserted at once.


const row2 = {
  SingerId: 'Id3b',
  Name: 'Joe West'
};

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue multiple mutations until later calling `commit`.
  // Note that a callback is not passed to `insert`.
  transaction.insert('Singers', [
    row,
    row2
  ]);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The rows were inserted successfully.
    }
  });
});

replace(table, rows)

replace(table: string, rows: object | object[]): void;

Replace rows of data within a table.

Parameters
NameDescription
table string

The table to read from.

rows object | object[]

A map of names to values of data to insert into this table.

Returns
TypeDescription
void
Example 

const row = {
  SingerId: 'Id3',
  Name: 'Joe West'
};

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue this mutation until later calling `commit`.
  // Note that a callback is not passed to `replace`.
  transaction.replace('Singers', row);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The row was replaced successfully.
    }
  });
});

rollback(gaxOptions)

rollback(gaxOptions?: CallOptions): Promise<void>;

Roll back a transaction, releasing any locks it holds. It is a good idea to call this for any transaction that includes one or more queries that you decide not to commit.

Wrapper around .

Parameter
NameDescription
gaxOptions CallOptions

Request configuration options, See CallOptions for more details.

Returns
TypeDescription
Promise<void>

{Promise

Example 

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  transaction.rollback(function(err) {
    if (!err) {
      // Transaction rolled back successfully.
    }
  });
});

rollback(callback)

rollback(callback: spannerClient.spanner.v1.Spanner.RollbackCallback): void;
Parameter
NameDescription
callback RollbackCallback
Returns
TypeDescription
void

rollback(gaxOptions, callback)

rollback(gaxOptions: CallOptions, callback: spannerClient.spanner.v1.Spanner.RollbackCallback): void;
Parameters
NameDescription
gaxOptions CallOptions
callback RollbackCallback
Returns
TypeDescription
void

update(table, rows)

update(table: string, rows: object | object[]): void;

Update rows of data within a table.

Parameters
NameDescription
table string

The table to read from.

rows object | object[]

A map of names to values of data to insert into this table.

Returns
TypeDescription
void
Example 

const row = {
  SingerId: 'Id3',
  Name: 'Joe West'
};

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue this mutation until later calling `commit`.
  // Note that a callback is not passed to `update`.
  transaction.update('Singers', row);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The row was updated successfully.
    }
  });
});

upsert(table, rows)

upsert(table: string, rows: object | object[]): void;

Insert or update rows of data within a table.

Parameters
NameDescription
table string

The table to read from.

rows object | object[]

A map of names to values of data to insert into this table.

Returns
TypeDescription
void
Example 

const row = {
  SingerId: 'Id3',
  Name: 'Joe West'
};

database.runTransaction(function(err, transaction) {
  if (err) {
    // Error handling omitted.
  }

  // Queue this mutation until later calling `commit`.
  // Note that a callback is not passed to `upsert`.
  transaction.upsert('Singers', row);

  // Commit the transaction.
  transaction.commit(function(err) {
    if (!err) {
      // The row was updated or inserted successfully.
    }
  });
});

useInRunner()

useInRunner(): void;

Mark transaction as started from the runner.

Returns
TypeDescription
void

useOptimisticLock()

useOptimisticLock(): void;

Use optimistic concurrency control for the transaction.

In this concurrency mode, operations during the execution phase, i.e., reads and queries, are performed without acquiring locks, and transactional consistency is ensured by running a validation process in the commit phase (when any needed locks are acquired). The validation process succeeds only if there are no conflicting committed transactions (that committed mutations to the read data at a commit timestamp after the read timestamp).

Returns
TypeDescription
void