mysql - 如何修复插入后触发计数时mysql代码中的错误

Question

我正在设置triggerafter_inser，但我不知道如何解决

DELIMITER $$
USE `solocloud_dev_2`$$

DROP TRIGGER IF EXISTS table_10_summary_after_insert $$

CREATE TRIGGER table_10_summary_after_insert AFTER INSERT ON table_10
   FOR EACH ROW BEGIN
   DECLARE var INT;
   SET var=0;

   SELECT COUNT(*) FROM table_10_summary WHERE client_id = new.client_id;

   IF var > 0
   THEN 
       UPDATE table_10_summary SET records = records+1 WHERE client_id = new.client_id;

    ELSE
        INSERT INTO table_10_summary (new.client_id,1);
END$$

DELIMITER$$

Answer 1

您的触发器存在几个问题:

• 您需要从查询结果中SET var；就像现在一样，您没有设置此值

• IF block 必须以 END IF 终止

以下代码编译成功 in this DB Fiddle :

DELIMITER $$

DROP TRIGGER IF EXISTS table_10_summary_after_insert $$

CREATE TRIGGER table_10_summary_after_insert AFTER INSERT ON table_10
FOR EACH ROW 
BEGIN
    DECLARE var INT;

    SET var = (SELECT COUNT(*) FROM table_10_summary WHERE client_id = new.client_id);
    IF (var > 0) THEN 
        UPDATE table_10_summary SET records = records + 1 WHERE client_id = new.client_id;
    ELSE
        INSERT INTO table_10_summary VALUES(new.client_id,1);
    END IF;

END$$

DELIMITER ;