mysql多表join时候update更新数据的方法

mysql多表多表join时候时候update更新数据的方法更新数据的方法

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：

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=''

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

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

> 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);