如何选择一个peticular值空白,这是选择查询中的虚拟列? [英] How do I select one peticular value blank which is dummy column in select query ?
问题描述
这是我的选择查询
选择'dummy',*来自Employee_Details
这是我的输出
(无列名)UserId FirstName LastName City Designation用户名
dummy 19 aaa bbbb ccccc programmer ccccasasas
dummy 21 tttrt rtrttrt tryrt sdfdf默认
dummy 22 ttt ttt ghj ghj默认
dummy 23 ghj ghj ghj ghhhjghjh默认
dummy 20 yyyyyy wer wer wer默认
但是我想要userId = 20的空白值。 />
有可能吗?给我解决方案同样的
this is my select Query
select 'dummy', * from Employee_Details
this is my output
(No column name) UserId FirstName LastName City Designation UserName
dummy 19 aaa bbbb ccccc programmer ccccasasas
dummy 21 tttrt rtrttrt tryrt sdfdf Default
dummy 22 ttt ttt ghj ghj Default
dummy 23 ghj ghj ghj ghhhjghjh Default
dummy 20 yyyyyy wer wer wer Default
but I want blank value for userId = 20 .
Is is possible? Give me solution for the same
推荐答案
尝试联合
try union
select '', * from Employee_Details where userId = 20
union
select 'dummy', * from Employee_Details where userId <> 20
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