SQL創建臨時表

在數據庫查詢數據的時候，比如查詢出type需要根據不用的值，換一個別名，在程序中循環處理有點麻煩，現在有一個方法就是用臨時表跟查詢表連接查詢即可。所以現在需要新建一個臨時表，然後用左聯接聯合查詢。

1、新建臨時表

select '100' as val,'sc' as lx 
 UNION select '200' as val,'zy' as lx
 UNION select '300' as val,'bg' as lx 
 UNION select '600' as val,'yy' as lx 

2、連接查詢

select ty.*,ta.* from table ta 
 left join (select '100' as val,'sc' as lx 
 UNION select '200' as val,'zy' as lx
 UNION select '300' as val,'bg' as lx 
 UNION select '600' as val,'yy' as lx ) ty on ty.lx=ta.lx