default.sql

简单的sql语句 数据与汇总。 高手多多指点。

use northwind 
go

exec sp_help customers
go

use northwind 
go
select * from customers
go


create default df_cust  as 'unknow'
go 
/*创建默认*/
exec sp_bindefault df_cust,'customers.contactname'
go
/*绑定默认值到某列*/


/*上面连个步骤等价于下列代码
alter table customers 
add constraint df_cust default 'unknow' for contactname 
go
*/


/*
alter table customers 
add hobby varchar(10) not null default 'unkonw'
go
*/

IF EXISTS (SELECT contactname FROM customers
         WHERE contactname = 'unknow' )
   DROP DEFAULT datedflt
GO

alter table customers 
add constraint df_country default 'CH' for contactname 
go

exec sp_help customers
go

alter table customers
add age int not null default(20)
go 

alter table customers 
add hobby varchar(10) not null default 'unkonw'
go