Sql Server²éѯÊý¾Ý¼¯ÐÐÁл¥»»

Ðл»ÁУº
--> Éú³É²âÊÔÊý¾Ý±í: [tb]
IF OBJECT_ID('[tb]') IS NOT NULL
    DROP TABLE [tb]
GO
CREATE TABLE [tb] ([a] [int],[b] [int],[c] [int])
INSERT INTO [tb]
SELECT '3','9','5' UNION ALL
SELECT '5','2','7' UNION ALL
SELECT '6','3','8'
--SELECT * from [tb]
-->SQL²éѯÈçÏÂ:
select value maxnum from tb unpivot(value for type in(a,b,c)) b
########################################
Áл»ÐУº
´ý²¹³ä