Question

MYSQL：

DELIMITER $$
CREATE TRIGGER `Activation_code` BEFORE UPDATE ON `user_users` FOR EACH ROW BEGIN
    (CASE 
     WHEN (OLD.activation_code_time < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 15 MINUTE) AND OLD.activation_code <> NEW.activation_code) 
           THEN SET NEW.activation_code = (SELECT(ROUND((RAND() * (999999-100000))+100000))), NEW.activation_code_time = (SELECT(UNIX_TIMESTAMP())) 
           ELSE SET NEW.activation_code = OLD.activation_code, NEW.activation_code_time = OLD.activation_code_time
    END);
    (CASE      
      WHEN (OLD.forgotten_password_time < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 15 MINUTE) AND OLD.txt_key <> NEW.txt_key) 
           THEN SET NEW.forgotten_password_time = (SELECT(UNIX_TIMESTAMP()))
           ELSE SET NEW.forgotten_password_time = OLD.forgotten_password_time 
    END);
END
$$
DELIMITER ;

错误：

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'CASE 
     WHEN (OLD.activation_code_time < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTE' at line 2

任何人都可以告诉我如何解决此错误？为什么这个功能不起作用。我可以通过使用一个case和多个来解决这个问题，当一个语句带有else语句吗？

Answer 1

使用if代替case。

DELIMITER   $$
CREATE  TRIGGER `ACTIVATION_CODE` BEFORE UPDATE ON `user_users`
FOR EACH ROW 
BEGIN

    IF OLD.ACTIVATION_CODE_TIME < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 15  MINUTE)) AND OLD.ACTIVATION_CODE !=  NEW.ACTIVATION_CODE THEN
        SET NEW.ACTIVATION_CODE  = (ROUND((RAND()   *   (999999-100000))+100000));
        SET NEW.ACTIVATION_CODE_TIME = UNIX_TIMESTAMP();
    ELSE
        SET NEW.ACTIVATION_CODE = OLD.ACTIVATION_CODE;
        SET NEW.ACTIVATION_CODE_TIME = OLD.ACTIVATION_CODE_TIME;
    END IF;

    IF OLD.forgotten_password_time < UNIX_TIMESTAMP(DATE_SUB(NOW(), INTERVAL 15 MINUTE)) AND OLD.txt_key != NEW.txt_key THEN
        SET NEW.forgotten_password_time = UNIX_TIMESTAMP();
    ELSE 
        SET NEW.forgotten_password_time = OLD.forgotten_password_time;
    END IF;

END$$  
DELIMITER ;

Answer 2

您无法为SET块下的字段应用多个CASE值而是首先在字段上调用SET以根据CASE设置值。

以下更改可能会对您有所帮助。

DELIMITER $$

CREATE TRIGGER `Activation_code` BEFORE UPDATE ON `user_users`
FOR EACH ROW
BEGIN
    set NEW.activation_code = (
        CASE WHEN 
                OLD.activation_code_time < UNIX_TIMESTAMP( DATE_SUB(NOW(), INTERVAL 15 MINUTE) )
                AND OLD.activation_code <> NEW.activation_code
            THEN ROUND( ( RAND() * (999999-100000) ) + 100000 )
            ELSE OLD.activation_code
        END
        );
    set NEW.activation_code_time = (
        CASE WHEN 
                OLD.activation_code_time < UNIX_TIMESTAMP( DATE_SUB(NOW(), INTERVAL 15 MINUTE) )
                AND OLD.activation_code <> NEW.activation_code
            THEN UNIX_TIMESTAMP() 
            ELSE OLD.activation_code_time
        END
        );
    set NEW.forgotten_password_time = (
        CASE WHEN 
                OLD.forgotten_password_time < UNIX_TIMESTAMP( DATE_SUB(NOW(), INTERVAL 15 MINUTE) )
                AND OLD.txt_key <> NEW.txt_key
            THEN UNIX_TIMESTAMP() 
            ELSE OLD.forgotten_password_time
        END
        );
END;
$$

DELIMITER ;

MYSQL触发器查询语法错误

2 个答案: