sql语句:
复制代码 代码如下:
update item i,resource_library r,resource_review_link l set i.name=CONCAT('Review:',r.resource_name) where i.item_id=l.instance_id
and l.level='item' and r.resource_id=l.resource_id and i.name=''


JOIN UPDATE & JOIN DELETE
复制代码 代码如下:
update a
set a.schoolname = b.schoolname
from tb_Std as a join tb_Sch as b on a.School = b.School
where a.std_year = 2005
go
/*
(2 row(s) affected)
*/
select *
from tb_Std as a join tb_Sch as b on a.School = b.School
/*
A School A A School
2 2005 A A School A A School
3 2004 C A School C C School
4 2005 D D School D D School
(4 row(s) affected)
*/

复制代码 代码如下:
delete a
from table1 a, table2 b
where a.col1 = b.col1
and a.col2 = b.col2

The above SQL statement runs fine in SQL Server.
If the Oracle 9i has different syntax or if there is any other way to accomplish this with a single delete statement that would be really helpful.

> Hi,
>
> Is the following delete statement possible in Oracle 9i.
>
> delete a
> from table1 a, table2 b
> where a.col1 = b.col1
> and a.col2 = b.col2
>
> The above SQL statement runs fine in SQL Server.
>
> If the Oracle 9i has different syntax or if there is any other way to accomplish this with a single delete statement that would be really helpful.
>
> Thanx in advance.
>
> -Bheem
Bheem,
Try this:
DELETE FROM table1 a where exists (select 1 from table2 b
where a.col1 = b.col1 and a.col2 = b.col2);
Hope this helps,
Tom K.
标签:
join,update

免责声明:本站文章均来自网站采集或用户投稿,网站不提供任何软件下载或自行开发的软件! 如有用户或公司发现本站内容信息存在侵权行为,请邮件告知! 858582#qq.com
评论“mysql多表join时候update更新数据的方法”
暂无“mysql多表join时候update更新数据的方法”评论...

RTX 5090要首发 性能要翻倍!三星展示GDDR7显存

三星在GTC上展示了专为下一代游戏GPU设计的GDDR7内存。

首次推出的GDDR7内存模块密度为16GB,每个模块容量为2GB。其速度预设为32 Gbps(PAM3),但也可以降至28 Gbps,以提高产量和初始阶段的整体性能和成本效益。

据三星表示,GDDR7内存的能效将提高20%,同时工作电压仅为1.1V,低于标准的1.2V。通过采用更新的封装材料和优化的电路设计,使得在高速运行时的发热量降低,GDDR7的热阻比GDDR6降低了70%。