Question

我想更新massemail_emailmaster的GroupID列，并将其设置为massemail_groupmaster上存储的值。两个表都有GroupName列，我用它来加入子查询。但是以下查询给了我错误。错误消息是a3附近的语法不正确。我不明白这里的语法错误。请帮忙。

UPDATE [dbo].[massmail_emailmaster]  a3
set a3.GroupId =
      (select TOP 1 a1.GroupID from [dbo].[massmail_groupmaster] a1 
         join [dbo].[massmail_emailmaster] a2
      on a1.[groupname] = a2.[groupname]
where a3.[GroupName]=a2.[GroupName])

表[dbo]. [massmail_emailmaster]

的DDL

(ClientID, varchar(50)),
           (uid, int)
           (Name, varchar(100))
           (GroupName, varchar(100))
           (Email, varchar(100))
           GroupId, int)

表格的DDL

[dbo]. [massmail_groupmaster]
 (Clientid, varchar(50))
           ,(uid, int)
           ,(groupname, varchar(100))
(GroupId,int))

Answer 1

稍后在update子句中定义时，可以使用from中的别名。（这是一种“反常”的情况，其中别名在首次使用后定义。）

UPDATE a3 set GroupId = (select TOP 1 a1.GroupID from [dbo].[massmail_groupmaster] a1 where a1.[groupname] = a3.[groupname] ) FROM [dbo].[massmail_emailmaster] a3;

Answer 2

UPDATE  a2
SET a2.GroupId = (SELECT TOP 1 a.GroupID 
                   FROM [dbo].[massmail_groupmaster] a 
                   INNER JOIN [dbo].[massmail_emailmaster] b
                   ON a.[groupname] = b.[groupname]
                  ) 
FROM  [dbo].[massmail_emailmaster] a2
WHERE a.[groupname] = a2.[groupname]

sql server子查询加入错误

2 个答案: