一些工作和学习中经常用到的SQL语句

 CREATE table [表名] ( [自动编号字段] int IDENTITY (1,1) PRIMARY KEY , [字段1] nVarChar(50) default 默认值 null , [字段2] ntext null , [字段3] d

create table [表名]
(
[自动编号字段] int IDENTITY (1,1) PRIMARY KEY ,
[字段1] nVarChar(50) default '默认值' null ,
[字段2] ntext null ,
[字段3] datetime,
[字段4] money null ,
[字段5] int default 0,
[字段6] Decimal (12,4) default 0,
[字段7] image null ,
)

create table [表名]
(
[自动编号字段] int IDENTITY (1,1) PRIMARY KEY ,
[字段1] nVarChar(50) default '默认值' null ,
[字段2] ntext null ,
[字段3] datetime,
[字段4] money null ,
[字段5] int default 0,
[字段6] Decimal (12,4) default 0,
[字段7] image null ,
)

INSERT INTO [表名] (字段1,字段2) VALUES (100,'51WINDOWS.NET')

DELETE FROM [表名] WHERE [字段名]>100

UPDATE [表名] SET [字段1] = 200,[字段2] = '51WINDOWS.NET' WHERE [字段三] = 'HAIWA'

ALTER TABLE [表名] ADD [字段名] NVARCHAR (50) NULL

ALTER TABLE [表名] DROP COLUMN [字段名]

ALTER TABLE [表名] ALTER COLUMN [字段名] NVARCHAR (50) NULL

ALTER TABLE [表名] ADD CONSTRAINT 约束名 CHECK ([约束字段] <= '2000-1-1')

ALTER TABLE [表名] DROP CONSTRAINT 约束名

ALTER TABLE [表名] ADD CONSTRAINT 默认值名 DEFAULT '51WINDOWS.NET' FOR [字段名]

ALTER TABLE [表名] DROP CONSTRAINT 默认值名