/*====================================================
*描述：            存储过程知识点总结，以Northwind数据库的Employees表为例
======================================================*/

--========================1.没有参数的存储过程================
create procedure usp_NoParameterSelect
as
begin
select * from dbo.Employees
end

GO

--========================执行测试========================
EXECUTE usp_NoParameterSelect

GO
--=======================2.带参数的存储过程===================

create procedure usp_ParameterSelect
(
@employeeID INT
)
as

begin
select * from dbo.Employees
where EmployeeID = @employeeID
end

--=======================执行测试===========================
EXECUTE usp_ParameterSelect 1

GO
--=======================3.带多个参数的存储过程==================

create procedure usp_MultiParameterSelect
@employeeID INT,
@employeeFirstName nvarchar(10)--要加上参数类型的长度
as
begin
select * from dbo.Employees
where EmployeeID = @employeeID
and FirstName = @employeeFirstName
end

--========================执行测试===========================
EXECUTE usp_MultiParameterSelect 1,'Nancy'

GO

--=======================4.output输出存储过程====================
create procedure usp_OutputSelect
@employeeID int ,
@employeeFirstName nvarchar(10) output
as
begin
select @employeeFirstName = FirstName from Employees
where EmployeeID = @employeeID
end

--=======================执行测试=============================
declare @name nvarchar(10)
execute usp_OutputSelect 1,@name output
select @name as name
GO

--======================5.return输出存储过程======================

create procedure usp_ReturnSelect
@employeeFirstName nvarchar(10)
AS
begin
declare @employeeID INT
select @employeeID = EmployeeID from Employees
where FirstName = @employeeFirstName

return @employeeID --**返回值必须是INT类型**
end

GO

--======================执行测试===============================
declare @employeeID INT
execute @employeeID = usp_ReturnSelect 'Nancy'
print @employeeID

GO

--=====================6.同时有output和return输出的存储过程=============

create procedure usp_OutputAndReturnSelect
@firstName nvarchar(10),
@lastName nvarchar(20) output
as
begin
declare @employeeID INT;

select @employeeID = EmployeeID,@lastName=LastName from Employees
where FirstName = @firstName

return @employeeID
end

GO

--======================执行测试================================
declare @employeeID INT
declare @lastName nvarchar(20)
execute @employeeID = usp_OutputAndReturnSelect 'Nancy',@lastName output
select @employeeID,@lastName

/*===========================================================
*****************************未完待续***************************************
*============================================================*/