5. 参考文献 [Mysql Update with Subquery]( [MySQL子查询](
MySQL中的子查询(Subquery)是指嵌套在另一个查询中的查询。子查询可以出现在SELECT、FROM、WHERE、HAVING和UPDATE语句中。当子查询用在UPDATE语句中时,它允许你基于另一个表或同一表中的数据来更新记录。 相关优势 灵活性:子查询提供了在单个SQL语句中执行多个操作的能力。
It is possible to use a subquery in the WHERE clause as well. Just like in the previous examples, this can be done to remove the separate step of finding a value to be updated and then to run the query to update it. We can continue working with our example from the previous steps. ...
Works with: SQL Server, PostgreSQL (not Oracle, MySQL) You can use a subquery in theWITH clause(called a CTE or Common Table Expression) to update data in one table from another table. WITHsubqueryAS(SELECTaccount_id,account_number,person_idFROMaccount)UPDATEpersonSETaccount_number=subquery.acco...
insert with update的SQL insert触发器 在update on上创建触发器 Delete触发器with Update Subquery语句with Multirow delete、insert或update触发器之后的SQL Update触发器在插入后触发 SQL insert触发器条件语句和多行 在具有多个if/Case条件的sqlite update触发器中 使用"AFTER INSERT,UPDATE,DELETE“DML触发器。如何...
Here, the SQL query updates thefirst_nametoAlicein theCustomerstable for those who ordered aMonitorand whose shipping status isDelivered. UPDATE With Subquery Using a subquery within theWHEREclause can mimic theJOINbehavior in SQLite. For example, ...
接收一条Query后,会进行SQL解析,生成语法树,接下来会生成执行计划,选择最优的执行计划进行执行,对于一条SQL,可能有多种执行计划,观察和分析执行计划可以帮助开发人员以及DBA优化SQL. With the help of EXPLAIN, you can see where you should add indexes to tables so that the statement executes ...
Description: From version 4.1.1-alpha it seems to be not allowed to use UPDATE with a subquery. If you try my example you'll get: [Zeus] ERROR 1149: You have an error in your SQL syntax. Check the manual that corresponds to your MySQL server version for the right syntax to use ...
Subqueries are an important alternative toJOINwhen you want to perform updates based on a simple condition. With subqueries, you will avoid multiple complex tables by specifying the condition in the subquery. The following example shows how to use a subquery to update theSalestable with the latest...
The rows referenced in the TOP expression used with INSERT, UPDATE, or DELETE aren't arranged in any order. Parentheses delimiting expression in TOP are required in INSERT, UPDATE, and DELETE statements. For more information, see TOP (Transact-SQL). table_alias The alias specified in the UPDA...