2017-10-05 46 views
1

替换值的值我有两个表:SQL Server的更新,并从另一个表

连接

id user_id connection_info 
------------------------------ 
1 1  ... 
2 1  ... 
3 2  ... 

列表

id connection_id name 
----------------------- 
1  1   ... 
2  2   ... 
3  1   ... 

我现在有user_id“ s在lists.connection_id列。我想加入lists表,connections表由connections.user_id = lists.connection_id,然后用connections表中的相应ID替换lists.connection_id

+2

所以你尝试一些东西,失败?如果是的话请分享你的代码/错误。如果没有,尝试一个解决方案,并分享给人们一些工作。 – Tanner

回答

1

您可以使用UPDATE FROM这样的:

update l 
set l.connection_id = c.id 
from connections c join lists l on c.user_id = l.connection_id 

最初你想测试你要更新的内容,运行SELECT声明:

select l.connection_id as con_old 
    , c.id as con_new 
    , ... (other cols you might want to check) 
from connections c join lists l on c.user_id = l.connection_id 
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