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mysql多表join时候update更新数据的方法

  • 时间:2020-11-22 06:05 编辑: 来源: 阅读:
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摘要:mysql多表join时候update更新数据的方法
sql语句:
[u]复制代码[/u] 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
[u]复制代码[/u] 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) */
[u]复制代码[/u] 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.
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