WITHsubqueryAS(SELECTaccount_id,account_number,person_idFROMaccount)UPDATEpersonSETaccount_number=subquery.account_numberFROMsubqueryWHEREperson.person_id=subquery.person_id; This has the advantage of making the UPDATE part of the statement simple, and any complex logic for the query can go in the W...
UPDATE t_order t1 SET (ordername,orderprice)= (SELECT detailname,totalprice FROM t_detail WHERE t_detail.detailclasses =t1.classes) WHERE t1.orderid=1 例2: UPDATE A SET (A1, A2, A3) = (SELECT B1, B2, B3 FROM B WHERE A.ID = B.ID) WHERE ID IN (SELECT B.ID FROM B WHERE A...
UPDATE b SET (ClientName) = (SELECT name FROM a WHERE b.id = a.id) update set from 语句格式 当where和set都需要关联一个表进行查询时,整个update执行时,就需要对被关联的表进行两次扫描,显然效率比较低。 对于这种情况,Sybase和SQL SERVER的解决办法是使用UPDATE…SET…FROM…WHERE…的语法,实际上就是...
-- To update the status UPDATE Intellipaat SET status = 'Inactive' WHERE id IN (2, 4, 5); -- To check the updated records Select * from Intellipaat; Output: Explanation: The UPDATE statement updates the status of employees with IDs 2,4, and 5 to INACTIVE. Difference Between Updating...
SQL(Structured Query Language)简介 SQL(Structured Query Language)是一种用于访问和操作关系型数据库的标准编程语言,是用于数据库查询和程序设计的语言。其主要功能包括数据查询、数据操作、事务控制、数据定义和数据控制等。 SQL具有以下特点: 高级的非过程化编程语言:允许用户在高层数据结构上工作,不需要了解具体的数...
在实际操作数据库的时候,经常使用将update和select结合使用,例如使用select统计数据,然后update到对应的表,按照常规的实现方式,先select出来对应的数据,然后再执行update语句。 偶尔这样实现没问题,但是经常这么写就显得罗嗦了,其实有更好的方式。 先建两个测试表table1和table2,两个表的数据很简单,其记录条数分别为2...
Just like the SELECT statement, you need to specify columns and a table, but the UPDATE statement also requires the new data you want to store. This data can be dynamic or static, but as in introduction, well use static strings or numbers to change data
你可以理解为主键是特殊的唯一索引,那么既然上面的主键加的是行锁,那么这里的唯一索引在SQL执行时加的也会是行锁。我们可以来操作看看,依然以订单表为例。 先看看事务1执行语句: BEGIN; SELECT * FROM od_order WHERE order_no = 'BD02231000001002' FOR UPDATE; UPDATE od_order SET pay_time = '2023-02-...
SELECT 语句用于从表中选取数据,结果被存储在一个结果表中(称为结果集)。 编辑 SELECT... FROM...[WHERE...][GROUP BY...][HAVING...][ORDER BY...]; //一个基本查询语句中,至少要有select子句和from子句。其他四个子句根据需求来选择。 SELECT * FROM 表名; //查询表...
This SELECT statement ensures that the UPDATE statement affects only the records you need. Continuing with this scenario, the SELECT statement below returns a list of all records containing only those users who signed up within the last week. SELECT * FROM customers WHERE signup >= getDate() ...