请教:SELECT语句中怎样为含有表别名的列赋常量值
在表连接的SELECT语句中经常要对引用的列加上各自的表别名,例如:
SELECT a.colx,b.coly FROM table1 AS a ,table2 AS b WHERE a.name = b.name
但是,不能再对含有表别名的列赋常量值,例如不能这样:
SELECT a.colx = 常量,b.coly FROM table1 AS a,table2 AS b WHERE a.name = b.name
甚至也不能这样:
SELECT a.colx = 常量 FROM table1 AS a
请教大家解决的办法,多谢!