#class pq\Transaction

A database transaction.

NOTE:
Transactional properties like pq\Transaction::$isolation, pq\Transaction::$readonly and pq\Transaction::$deferrable can be changed after the transaction begun and the first query has been executed. Doing this will lead to appropriate SET TRANSACTION queries.

Constants:#

• READ_COMMITTED#
  Transaction isolation level where only rows committed before the transaction began can be seen.
• REPEATABLE_READ#
  Transaction isolation level where only rows committed before the first query was executed in this transaction.
• SERIALIZABLE#
  Transaction isolation level that guarantees serializable repeatability which might lead to serialization_failure on high concurrency.

Properties:#

• public (readonly) pq\Connection $connection#
  The connection the transaction was started on.
• public int $isolation# = pq\Transaction::READ_COMMITTED
  The transaction isolation level.
• public bool $readonly# = FALSE
  Whether this transaction performs read only queries.
• public bool $deferrable# = FALSE
  Whether the transaction is deferrable. See pq\Connection::startTransaction().

Functions:#

• Transaction::__construct#

  Start a transaction.

  void pq\Transaction::__construct(pq\Connection $conn[, bool $async = FALSE[, int $isolation = pq\Transaction::READ_COMMITTED[, bool $readonly = FALSE[, bool $deferrable = FALSE]]]])

• Transaction::commit#

  Commit the transaction or release the previous savepoint.

  void pq\Transaction::commit()

• Transaction::commitAsync#

  Asynchronously commit the transaction or release the previous savepoint.

  void pq\Transaction::commitAsync()

• Transaction::createLOB#

  Create a new large object and open it.

  pq\LOB pq\Transaction::createLOB([int $mode = pq\LOB::RW])

• Transaction::exportLOB#

  Export a large object to a local file.

  void pq\Transaction::exportLOB(int $oid, string $path)

• Transaction::exportSnapshot#

  Export a snapshot for transaction synchronization.

  string pq\Transaction::exportSnapshot()

• Transaction::exportSnapshotAsync#

  Asynchronously export a snapshot for transaction synchronization.

  void pq\Transaction::exportSnapshotAsync()

• Transaction::importLOB#

  Import a local file into a large object.

  int pq\Transaction::importLOB(string $local_path[, int $oid = pq\LOB::INVALID_OID)

• Transaction::importSnapshot#

  Import a snapshot from another transaction to synchronize with.

  void pq\Transaction::importSnapshot(string $snapshot_id)

• Transaction::importSnapshotAsync#

  Asynchronously import a snapshot from another transaction to synchronize with.

  void pq\Transaction::importSnapshotAsync(string $snapshot_id)

• Transaction::openLOB#

  Open a large object.

  pq\LOB pq\Transaction::openLOB(int $oid[, int $mode = pq\LOB::RW])

• Transaction::rollback#

  Rollback the transaction or to the previous savepoint within this transaction.

  void pq\Transaction::rollback()

• Transaction::rollbackAsync#

  Asynchronously rollback the transaction or to the previous savepoint within this transaction.

  void pq\Transaction::rollbackAsync()

• Transaction::savepoint#

  Create a SAVEPOINT within this transaction.

  void pq\Transaction::savepoint()

• Transaction::savepointAsync#

  Asynchronously create a SAVEPOINT within this transaction.

  void pq\Transaction::savepointAsync()

• Transaction::unlinkLOB#

  Unlink a large object.

  void pq\Transaction::unlinkLOB(int $oid)