mysql多表join时候update更新数据的方法
网络编程 2021-07-05 15:27www.168986.cn编程入门
如果item表的name字段为''就用resource_library 表的resource_name字段前面加上字符串Review更新它,他们的关联关系在表resource_review_link中。
sql语句
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
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)
/
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 acplish 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 acplish 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.
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
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)
/
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 acplish 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 acplish 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.
编程语言
- 如何快速学会编程 如何快速学会ug编程
- 免费学编程的app 推荐12个免费学编程的好网站
- 电脑怎么编程：电脑怎么编程网咯游戏菜单图标
- 如何写代码新手教学 如何写代码新手教学手机
- 基础编程入门教程视频 基础编程入门教程视频华
- 编程演示：编程演示浦丰投针过程
- 乐高编程加盟 乐高积木编程加盟
- 跟我学plc编程 plc编程自学入门视频教程
- ug编程成航林总 ug编程实战视频
- 孩子学编程的好处和坏处
- 初学者学编程该从哪里开始 新手学编程从哪里入
- 慢走丝编程 慢走丝编程难学吗
- 国内十强少儿编程机构 中国少儿编程机构十强有
- 成人计算机速成培训班 成人计算机速成培训班办
- 孩子学编程网上课程哪家好 儿童学编程比较好的
- 代码编程教学入门软件 代码编程教程