SAVEPOINT

savepoints

defining

SAVEPOINT

7

SQL - Language Statements

SAVEPOINT

define a new savepoint within the current transaction

SAVEPOINT

savepoint\_name

Description
===========

`SAVEPOINT` establishes a new savepoint within the current transaction.

A savepoint is a special mark inside a transaction that allows all
commands that are executed after it was established to be rolled back,
restoring the transaction state to what it was at the time of the
savepoint.

Parameters
==========

savepoint\_name

:   The name to give to the new savepoint.

Notes
=====

Use [`ROLLBACK TO`](#sql-rollback-to) to rollback to a savepoint. Use
[`RELEASE SAVEPOINT`](#sql-release-savepoint) to destroy a savepoint,
keeping the effects of commands executed after it was established.

Savepoints can only be established when inside a transaction block.
There can be multiple savepoints defined within a transaction.

Examples
========

To establish a savepoint and later undo the effects of all commands
executed after it was established:

    BEGIN;
        INSERT INTO table1 VALUES (1);
        SAVEPOINT my_savepoint;
        INSERT INTO table1 VALUES (2);
        ROLLBACK TO SAVEPOINT my_savepoint;
        INSERT INTO table1 VALUES (3);
    COMMIT;

The above transaction will insert the values 1 and 3, but not 2.

To establish and later destroy a savepoint:

    BEGIN;
        INSERT INTO table1 VALUES (3);
        SAVEPOINT my_savepoint;
        INSERT INTO table1 VALUES (4);
        RELEASE SAVEPOINT my_savepoint;
    COMMIT;

The above transaction will insert both 3 and 4.

Compatibility
=============

SQL requires a savepoint to be destroyed automatically when another
savepoint with the same name is established. In PostgreSQL, the old
savepoint is kept, though only the more recent one will be used when
rolling back or releasing. (Releasing the newer savepoint with
`RELEASE SAVEPOINT` will cause the older one to again become accessible
to `ROLLBACK TO SAVEPOINT` and `RELEASE SAVEPOINT`.) Otherwise,
`SAVEPOINT` is fully SQL conforming.

See Also
========
