mysql - 使用嵌套查询更新

Question

以下是我的查询和相关的错误。我究竟做错了什么？

update aaalogin 
  set name = 
      ( select aaacontactinfo.emailid 
        from aaacontactinfo 
        WHERE aaalogin.user_id = aaausercontactinfo.user_id 
          and aaausercontactinfo.contactinfo_id = aaacontactinfo.contactinfo_id
      );

我明白了

错误：“where 子句”中的未知列“aaausercontactinfo.user_id”

Answer 1

尝试

UPDATE aaalogin SET name =
(
    SELECT aaacontactinfo.emailid
    FROM aaacontactinfo, aaausercontactinfo
    WHERE aaalogin.user_id = aaausercontactinfo.user_id
    AND aaausercontactinfo.contactinfo_id = aaacontactinfo.contactinfo_id
);

子查询中不需要aalogin。如果使用，它甚至可能在子查询中返回多条记录。

Answer 2

aaausercontactinfo未包含在FROM表格列表中，请尝试：

UPDATE aaalogin SET name =
(
    SELECT aaacontactinfo.emailid
    FROM aaacontactinfo, aaalogin, aaausercontactinfo
    WHERE aaalogin.user_id = aaausercontactinfo.user_id
    AND aaausercontactinfo.contactinfo_id = aaacontactinfo.contactinfo_id
);