参考的例子如: -------------------------------------------------------------------------- -- Author : htl258(Tony) -- Date : 2010-04-22 20:28:29 -- Version:Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86) -- Jul 9 2008 14:43:34 -- Copyright (c) 1988-2008 Microsoft Corporation -- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3) -------------------------------------------------------------------------- --> 生成测试数据表:tbIF NOT OBJECT_ID('[tb]') IS NULL DROP TABLE [tb] GO CREATE TABLE [tb]([id] INT IDENTITY PRIMARY KEY,[REFERENCESCOL] AS ID*2,COL INT) INSERT [tb] SELECT 22 UNION ALL SELECT 33 GO -->SQL查询如下: SELECT * FROM [tb] /* id REFERENCESCOL COL ----------- ------------- ----------- 1 2 22 2 4 33(2 行受影响) */
col可以参照ID!不明白!能解释下不?....
估计是col是id的外键 insert into tb (id,col)values(1,null) insert into tb (id,col)values(2,null) insert into tb (id,col)values(3,1) insert into tb (id,col)values(4,2)
--------------------------------------------------------------------------
-- Author : htl258(Tony)
-- Date : 2010-04-22 20:28:29
-- Version:Microsoft SQL Server 2008 (RTM) - 10.0.1600.22 (Intel X86)
-- Jul 9 2008 14:43:34
-- Copyright (c) 1988-2008 Microsoft Corporation
-- Developer Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 3)
--------------------------------------------------------------------------
--> 生成测试数据表:tbIF NOT OBJECT_ID('[tb]') IS NULL
DROP TABLE [tb]
GO
CREATE TABLE [tb]([id] INT IDENTITY PRIMARY KEY,[REFERENCESCOL] AS ID*2,COL INT)
INSERT [tb] SELECT 22
UNION ALL SELECT 33
GO
-->SQL查询如下:
SELECT * FROM [tb]
/*
id REFERENCESCOL COL
----------- ------------- -----------
1 2 22
2 4 33(2 行受影响)
*/
insert into tb (id,col)values(1,null)
insert into tb (id,col)values(2,null)
insert into tb (id,col)values(3,1)
insert into tb (id,col)values(4,2)