目录

RELEASE SAVEPOINT

用于移除先前保存点的 SQL 命令

RELEASE SAVEPOINT 是一个用于移除先前定义的 savepoint 的事务命令。

RELEASE SAVEPOINT 在 PostgreSQL 8.0 中引入。

用法

RELEASE SAVEPOINT 会移除事务中先前定义的保存点。如果释放的保存点之后还有其他保存点，那么那些保存点也会被一并释放。

变更历史

示例

RELEASE SAVEPOINT 的基本执行示例

postgres=# BEGIN;
BEGIN

postgres=*# INSERT INTO foo VALUES(1);
INSERT 0 1

postgres=*# SAVEPOINT s1;
SAVEPOINT

postgres=*# INSERT INTO foo VALUES(2);
INSERT 0 1

postgres=*# SAVEPOINT s2;
SAVEPOINT

postgres=*# INSERT INTO foo VALUES(3);
INSERT 0 1

postgres=*# RELEASE SAVEPOINT s2;
RELEASE

此时，只能回滚到保存点 s1，或回滚整个事务。

postgres=*# ROLLBACK TO SAVEPOINT s2;
ERROR:  savepoint "s2" does not exist

postgres=!# ROLLBACK TO SAVEPOINT s1;
ROLLBACK

如果释放的保存点之后还存在其他保存点，它们也将被一并释放。

postgres=# BEGIN;
BEGIN

postgres=*# INSERT INTO foo VALUES(1);
INSERT 0 1

postgres=*# SAVEPOINT s1;
SAVEPOINT

postgres=*# INSERT INTO foo VALUES(2);
INSERT 0 1

postgres=*# SAVEPOINT s2;
SAVEPOINT

postgres=*# RELEASE SAVEPOINT s1;
RELEASE

postgres=*# ROLLBACK TO SAVEPOINT s2;
ERROR:  savepoint "s2" does not exist

分类

SQL 命令, 事务命令, 事务

另请参阅

SAVEPOINT, ROLLBACK TO SAVEPOINT

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