SQL Server子查询实例

 

例子一

SELECT COUNT(*) FROM
(  
    SELECT  [PersonID]
    FROM    [tbiz_AssScore]
    WHERE [ProjectID]=65
    GROUP BY PersonID 
) M

语法说明: 1).FROM后面跟小括号; 2)第7行小括号后面"空格"写上一字母标识