在項(xiàng)目中經(jīng)常遇到求每個(gè)類別最新顯示的數(shù)據(jù)，比如顯示某某某類別最新更新的5條數(shù)據(jù)。特寫下這個(gè)sql記錄于此：
-- =============================================
-- 作者: Rising_Sun>
-- 創(chuàng)建日期: 2012-9-28>
-- 描述: 顯示每個(gè)類別下最新更新的n條數(shù)據(jù)>
-- =============================================
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(jié)婚了','2011-10-11')
INSERT INTO @t VALUES(5,'八卦新聞','劉德華當(dāng)?shù)?,'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(cái)經(jīng)新聞','股票跌破2800點(diǎn)','2011-10-12')
INSERT INTO @t VALUES(8,'財(cái)經(jīng)新聞','人民幣首次降息','2011-10-10')
--每個(gè)類別最新顯示數(shù)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
