重复密钥的MySQL回滚

Question

我期待着在出现错误的情况下使用transaction和rollback (如重复的键或其他)。

当我禁用自动提交时，当错误出现时，事务已经提交，即使它们不应该提交。

下面是我的代码的解析：

CREATE TABLE `Users` (
  `user_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

CREATE TABLE `Miscs` (
  `misc_id` int(11) DEFAULT NULL,
  PRIMARY KEY (`misc_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

SET @@AUTOCOMMIT = 0;

BEGIN;
    INSERT INTO Miscs ( misc_id ) VALUES('1');
    INSERT INTO Users ( user_id ) VALUES('1');
    INSERT INTO Miscs ( misc_id ) VALUES('2');
COMMIT;

BEGIN;
    INSERT INTO Miscs ( misc_id ) VALUES('3');
    INSERT INTO Users ( user_id ) VALUES('2');
    INSERT INTO Miscs ( misc_id ) VALUES('4');
COMMIT;

BEGIN;
    INSERT INTO Miscs ( misc_id ) VALUES('5');
    INSERT INTO Users ( user_id ) VALUES('1');
    -- should stop, rollback the transaction and skip to the next/last
    INSERT INTO Miscs ( misc_id ) VALUES('6');
COMMIT;

-- last transaction
BEGIN;
    INSERT INTO Miscs ( misc_id ) VALUES('7');
    INSERT INTO Users ( user_id ) VALUES('4');
    INSERT INTO Miscs ( misc_id ) VALUES('8');
COMMIT;

SET @@AUTOCOMMIT = 1;

但结果却很奇怪：

Users :
1
2
3

Miscs :
1
2
3
4
5
6
7
8

谢谢你的帮助。

Answer 1

在应用程序中，我会这样写-

START TRANSACTION
TRY
  INSERT
  INSERT
  INSERT
  COMMIT
CATCH
  ROLLBACK

但是MySQL没有TRY-CATCH子句。我可以建议您这样做，使用一个DECLARE EXIT HANDLER语句-

  BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION  ROLLBACK;
    START TRANSACTION;
      INSERT INTO Miscs ( misc_id ) VALUES('1');
      INSERT INTO Users ( user_id ) VALUES('1');
      INSERT INTO Miscs ( misc_id ) VALUES('2');
    COMMIT;
  END;

  BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION  ROLLBACK;
    START TRANSACTION;
      INSERT INTO Miscs ( misc_id ) VALUES('3');
      INSERT INTO Users ( user_id ) VALUES('2');
      INSERT INTO Miscs ( misc_id ) VALUES('4');
    COMMIT;
  END;

  BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION  ROLLBACK;
    START TRANSACTION;
      INSERT INTO Miscs ( misc_id ) VALUES('5');
      INSERT INTO Users ( user_id ) VALUES('1');
      -- should stop, rollback the transaction and skip to the next/last
      INSERT INTO Miscs ( misc_id ) VALUES('6');
    COMMIT;
  END;

  BEGIN
    DECLARE EXIT HANDLER FOR SQLEXCEPTION  ROLLBACK;
    START TRANSACTION;
      INSERT INTO Miscs ( misc_id ) VALUES('7');
      INSERT INTO Users ( user_id ) VALUES('4');
      INSERT INTO Miscs ( misc_id ) VALUES('8');
    COMMIT;
  END;

从存储过程运行此代码，因为在MySQL中不能在脚本中使用声明处理程序。

Answer 2

请参阅this link

如果未在语句中指定IGNORE选项，则SQL键重复错误将回滚

语句。