插入前创建mysql触发器（语法错误）

Question

嗨，我正在创建一些触发器来更新插入查询中的值，然后再插入这样的行

    CREATE TRIGGER `Insert members in Posts` BEFORE INSERT ON
    `posts` FOR EACH ROW
    BEGIN
        DECLARE name_ varchar(100); 
        DECLARE contact_ varchar(16); 
        DECLARE status_ int; 
        DECLARE deleted_ int;
    SELECT
        `members`.`name`,
        `members`.`contact`,
        `members`.`status`,
        `members`.`deleted`
    INTO name_, contact_, status_, deleted_
FROM
    `members`
WHERE
    `members`.`member_id` = NEW.member_id;
SET NEW.member_name = name_;
SET NEW.member_contact = contact_;
SET NEW.member_status = status_;
SET NEW.member_deleted = deleted;
END

但我收到了这样的错误

You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near '' at line 4

我有点困惑第 4 行的错误是什么。请解释一下。 谢谢。

Answer 1

例如，根据使用的客户端/IDE，您可能需要设置分隔符

 drop trigger if exists t;
   delimiter $$
   CREATE TRIGGER t BEFORE INSERT ON
    `posts` FOR EACH ROW
    BEGIN
        DECLARE name_ varchar(100); 
        DECLARE contact_ varchar(16); 
        DECLARE status_ int; 
        DECLARE deleted_ int;
    SELECT
        `members`.`name`,
        `members`.`contact`,
        `members`.`status`,
        `members`.`deleted`
    INTO name_, contact_, status_, deleted_
FROM
    `members`
WHERE
    `members`.`member_id` = NEW.member_id;
SET NEW.member_name = name_;
SET NEW.member_contact = contact_;
SET NEW.member_status = status_;
SET NEW.member_deleted = deleted;
END $$
delimiter ;

请查看https://dev.mysql.com/doc/refman/8.0/en/stored-routines.html