SQL取分组Top n条记录（转）

use Northwind

Select * FROM orders A Where EXISTS           (Select COUNT(1)          FROM orders          Where employeeid = A.employeeid AND orderid > A.orderid          HAVING COUNT(1) < 3) ORDER BY EmployeeID

语义：在库Northwind中查询表Orders里按EmployeeID分组，每个EmployeeID取前三条OrderID最大的记录

转载于:https://www.cnblogs.com/n666/archive/2010/02/22/2190952.html