SQL 2005 新功能

时间：2011-05-21 来源：独孤伤

1. TOP 表达式
SQL Server 2000的TOP是个固定值，是不是觉得不爽，现在改进了。

--前n名的订单

declare @n int

set @n = 10

select TOP(@n) * from Orders
2. 分页
不知各位过去用SQL Server 2000是怎么分页的，大多都用到了临时表。SQL Server 2005一句话就支持分页，性能据说也非常不错。
select * from(
    select OrderId, Freight, ROW_NUMBER() OVER(order by Freight) as row from Orders
) a
where row between 20 and 30

3. 排名
select * from(
    select OrderId, Freight, RANK() OVER(order by Freight) as rank from Orders
) a
where rank between 20 and 30

4. try ... catch
SQL Server 2000没有异常，T-SQL必须逐行检查错误代码，对于习惯了try catch程序员，2005是不是更加亲切：
SET XACT_ABORT ON  -- 打开 try功能
BEGIN TRY
    begin tran
        insert into Orders(CustomerId) values(-1)
    commit tran
    print 'commited'
END TRY
BEGIN CATCH
    rollback
    print 'rolled back'
END CATCH

5. 通用表达式CTE
通过表达式可免除你过去创建临时表的麻烦。 --例子：结合通用表达式进行分页
WITH OrderFreight AS(
    select OrderId, Freight, ROW_NUMBER() OVER(order by Freight) as row from Orders
)
select OrderId, Freight from OrderFreight where row between 10 and 20
6. 直接发布Web Service
这个比较酷，.NET, IIS都不需要了，通过Windows 2003的HTTP Protocol Stack直接发布WebService,用这个功能需要Windows 2003 sp1
--DataSet CustOrdersOrders(string customerID)
CREATE ENDPOINT Orders_Endpoint
state=started
as http(
    path='/sql/orders',
    AUTHENTICATION=(INTEGRATED),
    ports=(clear)
)
for soap(
    WebMethod 'CustOrdersOrders'(
        name='Northwind.dbo.CustOrdersOrders'
    ),

    wsdl=default,
    database='Northwind',
    namespace='http://mysite.org/'
)