将PostgreSQL存储过程作为一个事务执行 [英] Execute postgreSQL stored procedure as one transaction

问题描述

我正在使用PostgreSQL 9.3，并且创建了一些包含几个语句的存储过程.我正在准备好的语句的帮助下在Java应用程序中调用此存储过程.

I'm using PostgreSQL 9.3 and I have some stored procedures created which contains several statements. I'm calling this stored procedures in a Java application with the help of a prepared statement.

现在，我已经阅读到存储过程中的每个语句都作为事务执行，即在每个语句之后执行一次commit.但是我想要的是将整个存储过程作为一个事务执行，即仅执行一次提交.

Now I've read that each statement inside the stored procedure is executed as a transaction, i.e. one commit after each statement. But what I want is to have the whole stored procedure executed as one transaction, i.e. only one commit.

我该怎么做?也许在JDBC级别上禁用自动提交?

How can I do this? Perhaps deactivating autocommit on the JDBC level?

推荐答案

基本上，存储过程是原子的，并且作为一个事务执行.

Well, basically stored procedures are atomic in nature and executed as one transaction.

CREATE TABLE xxx (id int PRIMARY KEY);

CREATE OR REPLACE FUNCTION f() RETURNS void AS $$
DECLARE
  len int;
BEGIN
  RAISE NOTICE 'Transaction ID: %', TXID_CURRENT();
  INSERT INTO xxx VALUES (1);

  RAISE NOTICE 'Transaction ID: %', TXID_CURRENT();
  INSERT INTO xxx VALUES (2);

  RAISE NOTICE 'Transaction ID: %', TXID_CURRENT();
  SELECT COUNT(*) FROM xxx INTO len;
  RAISE NOTICE 'Number of records: %', len;

  RAISE NOTICE 'Transaction ID: %', TXID_CURRENT();

  -- results in unique constraint violation
  UPDATE xxx SET id = 3;
END;
$$ LANGUAGE plpgsql;

然后尝试从psql调用f().

stackoverflow=# show autocommit;
 autocommit 
------------
 on
(1 row)

stackoverflow=# SELECT f();
NOTICE:  Transaction ID: 15086
NOTICE:  Transaction ID: 15086
NOTICE:  Transaction ID: 15086
NOTICE:  Number of records: 2
NOTICE:  Transaction ID: 15086
ERROR:  duplicate key value violates unique constraint "xxx_pkey"
DETAIL:  Key (id)=(3) already exists.
CONTEXT:  SQL statement "UPDATE xxx SET id = 3"
PL/pgSQL function f() line 20 at SQL statement

stackoverflow=# SELECT * FROM xxx;
id 
----
(0 rows)

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