SQL Server 2005新功能-TSQL

SQL Server 2005相对于SQL Server 2000改进很大，有些还是非常实用的。

举几个例子来简单说明 这些例子我引用了Northwind库。

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。

--按Freight从小到大排序，求20到30行的结果; 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。www.mypchelp.cn

--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 特别，通过表达式还支持递归。

6. 直接发布Web Service 想要把store procedure变成Web Service就用这个吧，.NET, IIS都不需要，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/'; ) Web Service就发布好了，敲入http://localhost/sql/orders?wsdl得到wsdl