1 情境 deletefromtest1 t1wherenotexists(select1fromtest2 t2wheret1.id=t2.id ); 以上sql报错: ERROR 1064 (42000): 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 't1 where not exists (select 1 from ...
DELETEFROMusersWHERENOTEXISTS(SELECT1FROMordersWHEREorders.user_id=users.id); 1. 2. 3. 4. 代码解释: DELETE FROM users:指定我们要从users表中删除记录。 WHERE NOT EXISTS (...):这个条件判断如果在orders表中找不到与users表中对应的user_id,则满足删除条件。 SELECT 1 FROM orders WHERE orders.user...
mysql> delete from test1 t1 where not exists (select 1 from test2 t2 where t1.id=t2.id); ERROR 1064 (42000): 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 't1 where not exists (select 1 from ...
如果在MaxCompute客户端(odpscmd)执行,需要输入yes|no确认。 delete from acid_delete_t where not exists (select * from acid_delete_s where acid_delete_t.id=acid_delete_s.id); --查看结果表中只有id为2、3的数据。 select * from acid_delete_t; +---+---+---+ | id | value1 | value2 ...
DELETE结合EXISTS示例 假设我们有两个表:orders和customers,它们之间存在一对多的关系,即一个顾客可以有多个订单。我们的目标是删除没有订单的顾客。 首先,我们可以使用SELECT语句和EXISTS子查询来查找没有订单的顾客: SELECT*FROMcustomersWHERENOTEXISTS(SELECT*FROMordersWHEREorders.customer_id=customers.id) ...
既然 EXISTS 很快可以试试下面这样。特别适合 temp 很大的时候，和 u 表 join 起来后中间表太大的情况。SQL code?1234567891011121314151617181920 INSERT INTO #TSELECT id, 1 AS DeleteFlag FROM [u] WHERE dbId = 2; UPDATE #T SET DeleteFlag = 0 WHERE EXISTS ( SELECT 1 FROM ...
SQL语句关联删除delete d from tb_clfb dwhere not exists( select 1 from ( select c.CAR_NO,a.r
; ERROR 1064 (42000): 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 't1 where not exists (select * from test2 t2 where t1.testcol = t2.testcol)' at line 1 # try to delete without first ...
unique_subquery PRIMARY,IDX_PAY_MAIN_PAY_TIME PRIMARY 98 func 1 46.46 Using where not exists 子查询下优化器实现: UPDATE pay_stream a SET a.return_amount = 0 WHERE NOT EXISTS (SELECT b.pay_id FROM pay_main b WHERE a.pay_id = b.pay_id AND b.pay_time > '2017-08-12 00:00:00'...
deletefromtb_scwherenotexists(selectnullfromtb_sc a, (selectstudentid,courseid,max(score)asscorefromtb_scgroupbystudentid,courseid) bwherea.studentid=b.studentidanda.courseid=b.courseidanda.score=b.scoreandtb_sc.id=a.id) 优化方案3: 这种方案适用于delete语句太简单而删除数据较多的场合: ...