更新时间:2024-06-03 GMT+08:00

Package支持自治事务

自治事务可以在package中的存储过程或者函数中定义,标识符为PRAGMA AUTONOMOUS_TRANSACTION,其余语法与创建package中存储过程或函数语法相同,请参见CREATE PACKAGE,示例如下。

--建表
gaussdb=# CREATE TABLE t2(a INT, b INT);
CREATE TABLE
gaussdb=# INSERT INTO t2 VALUES(1,2);
INSERT 0 1
gaussdb=# SELECT * FROM t2;
 a | b 
---+---
 1 | 2
(1 row)

--创建包含自治事务的PACKAGE中的存储过程和函数
gaussdb=# CREATE OR REPLACE PACKAGE autonomous_pkg AS
  PROCEDURE autonomous_4(a INT, b INT);
  FUNCTION autonomous_32(a INT ,b INT) RETURN INT;
END autonomous_pkg;
/
CREATE PACKAGE
gaussdb=# CREATE OR REPLACE PACKAGE BODY autonomous_pkg AS
PROCEDURE autonomous_4(a INT, b INT)  AS 
DECLARE 
 num3 INT := a;
 num4 INT := b;
 PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
	INSERT INTO t2 VALUES(num3, num4); 
END;
FUNCTION autonomous_32(a INT ,b INT) RETURN INT AS 
DECLARE 
	PRAGMA AUTONOMOUS_TRANSACTION;
BEGIN
	INSERT INTO t2 VALUES(a, b);
	RETURN 1;
END;
END autonomous_pkg;
/
CREATE PACKAGE BODY

--创建调用PACKAGE自治事务存储过程和函数的普通存储过程
gaussdb=# CREATE OR REPLACE PROCEDURE autonomous_5(a INT, b INT)  AS 
DECLARE
va INT;
BEGIN
	INSERT INTO t2 VALUES(666, 666);
	autonomous_pkg.autonomous_4(a,b);
        va := autonomous_pkg.autonomous_32(a + 1, b + 1);
	ROLLBACK;
END;
/
CREATE PROCEDURE
--调用普通存储过程
gaussdb=# SELECT autonomous_5(11,22);
 autonomous_5 
--------------

(1 row)

--查看表结果
gaussdb=# SELECT * FROM t2 ORDER BY a;
 a  | b  
----+----
  1 |  2
 11 | 22
 12 | 23
(3 rows)

gaussdb=# DROP TABLE t2;
DROP TABLE

上述例子,最后在回滚的事务块中执行包含package自治事务的存储过程和函数,直接说明了自治事务的特性,即主事务的回滚不会影响自治事务已经提交的内容。