-- =============================================
-- 作者:  Rising_Sun>
-- 創建日期: 2012-9-28>
-- 描述: 顯示每個類別下最新更新的n條數據>
-- =============================================
DECLARE @t TABLE 
(
 NewsId INT,
 NewsType NVARCHAR(20),
 NewsTitle NVARCHAR(50),
 AddTime DATETIME
)
INSERT INTO @t VALUES(1,'體育新聞','火箭贏了','2011-10-11')
INSERT INTO @t VALUES(2,'體育新聞','劉翔因傷退出','2011-10-12')
INSERT INTO @t VALUES(3,'體育新聞','奧尼爾減肥成功','2011-10-13')
INSERT INTO @t VALUES(4,'八卦新聞','鳳姐結婚了','2011-10-11')
INSERT INTO @t VALUES(5,'八卦新聞','劉德華當爹了','2011-10-12')
INSERT INTO @t VALUES(6,'八卦新聞','蒼老師來中國宣傳了','2011-10-13')
INSERT INTO @t VALUES(7,'財經新聞','股票跌破2800點','2011-10-12')
INSERT INTO @t VALUES(8,'財經新聞','人民幣首次降息','2011-10-10')
--每個類別最新顯示數量
DECLARE @ShowNums INT
SET @ShowNums=2
SELECT * FROM 
(
 SELECT NewsId,NewsTitle,NewsType,AddTime,
     ROW_NUMBER() OVER(PARTITION BY NewsType ORDER BY AddTime DESC) AS RowIndex 
FROM @t
 ) AS T
WHERE RowIndex =@ShowNums