[英]mysql transaction - roll back on any exception
Is it possible to roll back automatically if any error occurs on a list of mysql commands?如果 mysql 命令列表发生任何错误,是否可以自动回滚?
for example something along the lines of:例如:
begin transaction;
insert into myTable values1 ...
insert into myTable values2 ...; -- will throw an error
commit;
now, on execute i want the whole transaction to fail, and therefore i should NOT see values1 in myTable.现在,在执行我希望整个交易失败,因此我不应该看到值1在myTable的。 but unfortunately the table is being pupulated with values1 even though the transaction has errors.
但不幸的是,即使交易有错误,该表也会使用 values1。
any ideas how i make it to roll back?任何想法我如何让它回滚? (again, on any error)?
(再次,任何错误)?
EDIT - changed from DDL to standard SQL编辑 - 从 DDL 更改为标准 SQL
You can use 13.6.7.2.您可以使用13.6.7.2。 DECLARE ... HANDLER Syntax in the following way:
DECLARE ... HANDLER 语法如下:
DELIMITER $$
CREATE PROCEDURE `sp_fail`()
BEGIN
DECLARE `_rollback` BOOL DEFAULT 0;
DECLARE CONTINUE HANDLER FOR SQLEXCEPTION SET `_rollback` = 1;
START TRANSACTION;
INSERT INTO `tablea` (`date`) VALUES (NOW());
INSERT INTO `tableb` (`date`) VALUES (NOW());
INSERT INTO `tablec` (`date`) VALUES (NOW()); -- FAIL
IF `_rollback` THEN
ROLLBACK;
ELSE
COMMIT;
END IF;
END$$
DELIMITER ;
For a complete example, check the following SQL Fiddle .有关完整示例,请查看以下SQL Fiddle 。
You could use EXIT HANDLER if you for example need to SIGNAL a specific SQL EXCEPTION in your code.例如,如果您需要在代码中发出特定的 SQL EXCEPTION 信号,则可以使用 EXIT HANDLER。 For instance:
例如:
DELIMITER $$
CREATE PROCEDURE `sp_fail`()
BEGIN
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK; -- rollback any changes made in the transaction
RESIGNAL; -- raise again the sql exception to the caller
END;
START TRANSACTION;
insert into myTable values1 ...
IF fail_condition_meet THEN
SIGNAL SQLSTATE '45000' SET MESSAGE_TEXT = 'Custom error detected.', MYSQL_ERRNO = 2000;
END IF;
insert into myTable values2 ... -- this will not be executed
COMMIT; -- this will not be executed
END$$
DELIMITER ;
The above solution are good but to make it even simpler上面的解决方案很好,但让它更简单
DELIMITER $$
CREATE PROCEDURE `sp_fail`()
BEGIN
DECLARE EXIT HANDLER FOR SQLEXCEPTION
BEGIN
ROLLBACK; -- rollback any error in the transaction
END;
START TRANSACTION;
insert into myTable values1 ...
insert into myTable values2 ... -- Fails
COMMIT; -- this will not be executed
END$$
DELIMITER ;
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