sql 学习笔记之:存储过程和用户自定义函数
2009-05-21 13:28
一:存储过程的简单创建,修改与删除 use AdventureWorks
go create proc spEmployee as select * from HumanResources.Employee 执行上面的代码就创建了一个存储过程
如果想运行这个存储过程
可以直接执行exec spEmployee这个语句
2.更改存储过程
ALTER proc [dbo].[spEmployee]
as select top 13 * from HumanResources.Employee 3.删除存储过程
drop proc dbo.spEmployee
二:存储过程的输入参数和输出参数 1.有输入参数的存储过程 use AdventureWorks
go create proc spEmployee @LastName nvarchar(50) = null as if @LastName is null select top 13 * from HumanResources.Employee else select top 10 * from HumanResources.Employee 查看该存储过程的结果可以用 exec spEmployee '123' 或直接exec spEmployee 存储过程的重载...
2.有输出参数的存储过程 use AdventureWorks
go alter proc spEmployee @LastName nvarchar(50) = null output as if @LastName is null begin print 'null' return '123' end else begin print @LastName return '456' end 看第一个测试该存储过程的语句
declare @myval nvarchar(50)
输出null 123exec @myval = spEmployee @myval output print @myval 第二个测试该存储过程的语句
declare @myval nvarchar(50)
set @myval = 'xland' exec @myval = spEmployee @myval output print @myval 输出xland 456
三:用户定义函数
1.返回标量值的用户定义函数 先做一个简单的日期处理函数 把长日期缩短成短日期 Create function dbo.DayOnly(@date datetime)
returns varchar(12) as begin return convert(varchar(12),@date,101) end 为了测试上面的函数先做个脚本
use Accounting
declare @counter int set @counter = 1 while @counter <= 10 begin insert into Orders values(1,dateadd(mi,@counter,getdate()),1) set @counter = @counter +1 end 然后检索这个脚本 新插入的数据记录
use Accounting
select * from orders where dbo.DayOnly(date1) = dbo.DayOnly(getdate()) 2.返回表的用户定义函数
先看例子 use AdventureWorks
go create function dbo.fnContactSearch(@LastName nvarchar(50)) returns table as return (select * from Person.Contact where LastName like @LastName+'%') 执行这个例子
use AdventureWorks
select * from fnContactSearch('Ad') 3.综合例子:返回表,有输入参数
use xland
go create function dbo.funGetMytable (@id as int) returns @allrows table ( id int not null, title nvarchar(max) null ) as begin insert into @allrows select id,title from mytable where id = @id return end go 执行这个例子
select * from funGetMytable(1)
|