使用CTE替换派生表语法

重构目标例子：http://www.cnblogs.com/insus/articles/1961688.html SELECT语句中需要使用到别名，<column> OR <expression> AS <column_alias>。

重构后的代码，请参考：

WITH  ASY  AS
(
     SELECT   YEAR (birthday)  AS   [ Year ] , [ Salary ]   FROM   [ dbo ] . [ Member ]
)
SELECT   [ Year ] , AVG ( [ Salary ] )  AS   [ AvgSalary ]
FROM  ASY
GROUP   BY   [ YEAR ]