Re: Update from another table where partial string exist in other table Sébastien F. May 27, 2022 04:42PM Re: Update from another table where partial string exist in other table Gideon Engelbrecht May 27, 2022 11:54PM Sorry, you can't reply to this topic. It has been closed. ...
[MySQL UPDATE JOIN: Updating Data in One Table Based on Values from Another Table]( [MySQL INNER JOIN]( 开始 经验丰富的开发者->新手 步骤1 经验丰富的开发者->新手 步骤2 经验丰富的开发者->新手 步骤3 经验丰富的开发者->新手 步骤4 经验丰富的开发者->新手 结束 经验丰富的开发者-->新手 MySQL...
创建触发器,当table1更新时,自动更新table2 CREATE TRIGGER update_table2_after_table1_update AFTER UPDATE ON table1 FOR EACH ROW BEGIN UPDATE table2 SET column2 = NEW.column1 WHERE condition; END; 在这个示例中,我们创建了一个名为update_table2_after_table1_update的触发器,它在table1的记录被更...
例如,UPDATE my_table SET column1 = (SELECT another_column FROM another_table WHERE condition) WHERE condition;。子查询可以返回单个值、多列值或多行值,具体取决于查询的需求。在使用子查询时,需要确保子查询返回的结果与要更新的列匹配,否则会引发错误。子查询的性能可能较低,特别是在处理大量数据时,因此...
SET my_column = (SELECT my_value FROM my_table WHERE condition) WHERE another_condition; 这个错误的原因是MySQL不允许在同一个查询中同时选择和更新同一个表。为了解决这个问题,你可以尝试以下几种方法:方法一:使用临时表你可以将选择操作的结果存储在一个临时表中,然后在更新操作中使用这个临时表。下面是示...
The INNODB_LOCKS table provides information about each lock that an InnoDB transaction has requested but not yet acquired, and each lock that a transaction holds that is blocking another transaction. 注意只有当事务因为获取不到锁而被阻塞即发生锁等待时 innodb_locks 表中才会有记录,因此当只有一个事务...
当ID等于2时,姓名更新为’Another Name’,邮箱更新为’anotheremail@example.com’。对于其他ID值,我们保持原来的姓名和邮箱不变。 代码示例 下面是一个完整的示例,展示了如何在MySQL中更新多个值。 -- 创建customers表CREATETABLEcustomers(idINTPRIMARYKEY,nameVARCHAR(50),emailVARCHAR(50),phoneVARCHAR(20));--...
mysql> UPDATE items > SET retail = retail * 0.9 > WHERE id IN > (SELECT id FROM items > WHERE retail / wholesale >= 1.3 AND quantity > 100); ERROR 1093 (HY000): You can't specify target table 'items' for update in FROM clause ...
...MySQL在触发DELETE/UPDATE/INSERT语句时就会自动执行所设置的操作,其他SQL语句则不会激活触发器。...1.3、触发器四要素 监视地点:table 监听事件:insert/update/delete 触发时间:after/before 触发事件:insert/update/delete 二、触发器用法...{ INSERT | UPDATE | DELETE } --同样也能设定触发的事件:它们...
Update from another tablePosted by: Matt H Date: August 30, 2007 08:18AM (Posted on Triggers forum as well) I log incoming file arrivals to a database logging the filename, shortcode and timestamp. I Then take the shortcode and look it up in another table, which gives me the ...