Question

我有一个使用以下3个表的问题：

1. Company (table)
CONAME
COPOINTS

2. Group_Member (table)
CONAME
NAME

3. Member (table)
NAME
MPOINTS

我希望在以下条件下获得正确的查询：

Update Member
Set MPOINTS=MPOINTS+5
Where Company.CONAME=Group_Member.CONAME
And
Group_Member.NAME=Member.NAME

请您更正以上查询？

Answer 1

在T-SQL（MS-SQL Server方言）中，这将是

Update Member
   set MPOINTS = MPOINTS + 5
  from Group_Member 
       join Company on Company.CONAME = Group_Member.CONAME
 where Group_Member.NAME = Member.NAME

我想提醒您，对于主要和外国关系，这些名称不是一个好的选择。在不违反主键约束的情况下，您永远无法更改名称。改为使用（数字，自动增量）ID列。

Answer 2

试试这个：

Update M
Set    MPOINTS=MPOINTS+5
from   Member M 
join   Group_Member GM
on     GM.NAME=M.NAME
join   Company C
on     C.CONAME=GM.CONAME

Answer 3

SQL Server 2005 +

UPDATE x
SET x.MPOINTS += 5
FROM (SELECT m.MPOINTS FROM Company c JOIN Group_Member g ON c.CONAME = g.CONAME
                                      JOIN Member m ON g.NAME = m.NAME) x

从3个不同的表中更新字段

3 个答案: