Sql 从多个表中选择
**嗨, 我有三张桌子:Sql 从多个表中选择,sql,sql-server,database,Sql,Sql Server,Database,**嗨, 我有三张桌子: users certification project 我需要为ech用户选择认证列表和项目列表,如: -------------------------------------------------------------------- userid | fullname | list of certification | list of project ----------------------------------------------
users
certification
project
我需要为ech用户选择认证列表和项目列表,如:
--------------------------------------------------------------------
userid | fullname | list of certification | list of project
--------------------------------------------------------------------
1 | xX | ITIL ,Cisco,.. | PROj 1 ,Proj 2 ...
我试试这个**
select users.fullname,users.team,users.jobtitle,certif= STUFF(
(SELECT ','+ certifiacte
FROM dbo.certification a
INNER JOIN dbo.Users ar ON ar.UserId = a.UserId
FOR XML PATH('')), 1, 1, ''),porj= STUFF(
(SELECT ','+ project
FROM dbo.project a
INNER JOIN dbo.Users ar ON ar.UserId = a.UserId
FOR XML PATH('')), 1, 1, '')
from Users
但问题是,我得到了保存在数据库中所有行中的所有认证和项目的列表。但我只需要为每个用户列出与他相关的项目和证书任何时候发生这种情况,都意味着你没有关联。子选择与外部查询无关 您需要这样做:
select ar.fullname,ar.team,ar.jobtitle,certif= STUFF(
(SELECT ','+ certifiacte
FROM dbo.certification a
WHERE ar.UserId = a.UserId
FOR XML PATH('')), 1, 1, ''),porj= STUFF(
(SELECT ','+ project
FROM dbo.project a
WHERE ar.UserId = a.UserId
FOR XML PATH('')), 1, 1, '')
from Users ar