关于union all的 问题 ，求教。
Select t_4.*
From (Select t_2.*
From Extend_Daily_Report t_2
Where t_2.Dr_User_Id = '1920 '
Union All
Select t_0.*
From Extend_Daily_Report t_0, Extend_Daily_Task t_1
Where t_0.Dr_Id = t_1.Dr_Id And t_1.Dt_Pm_Id = '1920 ' And (t_0.Dr_Status = '1 ' Or t_0.Dr_Status = '2 ') And
t_0.Dr_Dept_Id <> '2008 '
Union All
Select t_3.*
From Extend_Daily_Report t_3
Where (t_3.Dr_Status = '1 ' Or t_3.Dr_Status = '2 ') And t_3.Dr_Dept_Id = '2008 ' And t_3.dr_user_id <> '1920 ') t_4
工作中写了一个这样得 sql 实现了我的需求，感觉用union 不妥。由于小弟sql很差求教各位给出一个不用union all 的 sql 来实现这个功能。多谢
[解决办法]
select t.* from Extend_Daily_Report t, Extend_Daily_Task t_1
where t.Dr_Id = t_1.Dr_Id
and dr_User_id= '1920 '
And (t.Dr_Dept_Id <> '2008 ' and (t.Dr_Status = '1 ' Or t.Dr_Status = '2 ') )
and ((t.Dr_Status = '1 ' Or t.Dr_Status = '2 ') And t.Dr_Dept_Id = '2008 ' And t.dr_user_id <> '1920 ')
[解决办法]
Select t_0.*
From Extend_Daily_Report t_0, Extend_Daily_Task t_1
Where
t_0.Dr_User_Id = '1920 ' or
((t_0.Dr_Status = '1 ' Or t_0.Dr_Status = '2 ') And t_0.Dr_Dept_Id = '2008 ' And t_0.dr_user_id <> '1920 ') or
(t_0.Dr_Id = t_1.Dr_Id And t_1.Dt_Pm_Id = '1920 ' And (t_0.Dr_Status = '1 ' Or t_0.Dr_Status = '2 ') And t_0.Dr_Dept_Id <> '2008 ' )
[解决办法]
luguo
[解决办法]
用union all 效率上没什么影响吧，不用的话如果是一张表就把所有条件集合到一起就行了！
