转 --- 的两篇内容
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update多条Select出来的数据
好多朋友喜欢用游标解决此问题,但是执行速度狂慢!
其实解决起来很简单了:
先来个简单的:
把FLowER的Am_employee表的email,dept_id,ext_no多条数据按emp_no对应update到EmpBaseInfo表中:
update EmpBaseInfo
set email=b.Mail_account,dept_id=b.dept_code,ext_no=b.ext_no
from flower.flower.dbo.am_employee b
where b.emp_no=EmpBaseInfo.emp_no
复杂一点的:
多表select,并将结果对应插入到指定的表中:
update EmpBaseInfo
set Job_Rank=b.level_number
from flower.flower.dbo.am_employee a,flower.flower.dbo.am_level b,flower.flower.dbo.am_approver_level c
where a.emp_id=c.emp_id and b.level_number=c.level_number and a.emp_no=EmpBaseInfo.emp_no
取别名的:
update x
set Job_Rank=b.level_number
from flower.flower.dbo.am_employee a,flower.flower.dbo.am_level b,flower.flower.dbo.am_approver_level c,EmpBaseInfo x
where a.emp_id=c.emp_id and b.level_number=c.level_number and a.emp_no=x.emp_no
--另外一种方式: 临时表
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偶用临时表来解决
1、创建临时表#temp_1
SELECT card_id,sum(card_cost) as 'sum_cost'
INTO #tmp_1
FROM pos_t_vip_cost
GROUP by card_id
go
2、更新表pos_t_vip_info记录
UPDATE pos_t_vip_info,#tmp_1
SET pos_t_vip_info.card_amount = #tmp_1.sum_cost
WHERE pos_t_vip_info.card_id = #tmp_1.card_id
go
3、删除临时表
DROP TABLE #tmp_1
go
以上是参考资料
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update [StormPlatform120316].[dbo].[t_Assessment]
set Developers = le.DevelopmentPrincipal
from [StormPlatform120316].[dbo].[t_Assessment] a left join [StormPlatform0623].[dbo].[t_LeaderEvaluation] le on a.RequirementApplyID = le.RequirementApplyID and le.createtime in (select max(createtime) from [StormPlatform0623].[dbo].[t_LeaderEvaluation] group by RequirementApplyID)
where a.Developers = ''
Mysql的update语句
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2010-04-24 20:31 mysql update from 子查询mssql 子查询更新 update log set uin= b.uin from log a,logs b where a.accountuin = b.accountuin mysql 不支持 update 子查询更新 找了半天资料 终于搞定了... update `log` a inner join `logs` b on a.`accountuin` = b.`accountuin` set a.`uin` = b.`uin` where a.`accountuin` = b.`accountuin` 这样就能 将查询出来的字段批量更新过去了...
//delete的联合查询
Update Update XXX set XXX where 这种写法大家肯定都知道,才发现update和delete居然支持inner join的update方式,这个在表间关联来做更新和删除操作非常有用. 列子: Sql代码 update tb_User set pass='' from tb_User usr inner join tb_Address addr on usr.nAddressFK = addr.nAddressID where usr.id=123 update tb_User set pass='' from tb_User usr inner join tb_Address addr on usr.nAddressFK = addr.nAddressID where usr.id=123update的格式是 update t1 set t1.name=’Liu’ from t1 inner join t2 on t1.id = t2.tid MYSQL,ACCESS 写法如下: Sql代码 UPDATE mem_world AS mw1 INNER JOIN mem_world AS mw2 ON mw1.parentid = mw2.wid SET mw1.level = mw2.level WHERE mw2.baseid = 107 AND mw2.parentid = 0 AND mw2.size > 1; UPDATE mem_world AS mw1 INNER JOIN mem_world AS mw2 ON mw1.parentid = mw2.wid SET mw1.level = mw2.level WHERE mw2.baseid = 107 AND mw2.parentid = 0 AND mw2.size > 1; on是表连接的筛选条件 就是说,表连接后,会产生一个类似于临时的视图这么一个东西 where是从这个临时的视图中筛选数据的 所以,你首先要搞清,你的所谓的2个条件属于哪一种 Delete delete 语句也是类似 delete from t1 from t1 inner join t2 on t1.id = t2.tid 注意蓝色部分。 mysql: Sql代码 DELETE mwb FROM mem_world_building AS mwb INNER JOIN mem_world AS mw ON mwb.wid = mw.wid where mw.type between 11 and 15 and baseid = 107 and mw.parentid <> 0 and mw.size > 1; DELETE mwb FROM mem_world_building AS mwb INNER JOIN mem_world AS mw ON mwb.wid = mw.wid where mw.type between 11 and 15 and baseid = 107 and mw.parentid <> 0 and mw.size > 1; 下面是ORACLE的: Sql代码 DELETE TABLE1 where exists ( select 1 from table2 where and table1.khid=table2.khid and FWDWID=8); DELETE TABLE1 where exists ( select 1 from table2 where and table1.khid=table2.khid and FWDWID=8); Sql代码 DELETE TABLE1 where KHID exists ( select KHID from table2 where FWDWID=8) DELETE TABLE1 where KHID exists ( select KHID from table2 where FWDWID=8)