How to create userdefine and call :-

Create two table

CREATE TABLE[dbo].[Student1](

[RollNo] [decimal](18,0)NOTNULL,

[Name] [nvarchar](100)NULL,

CONSTRAINT[PK_Student1]PRIMARYKEYCLUSTERED

(

[RollNo]ASC

)WITH(PAD_INDEX=OFF,STATISTICS_NORECOMPUTE=OFF,IGNORE_DUP_KEY=OFF,ALLOW_ROW_LOCKS=ON,ALLOW_PAGE_LOCKS=ON)ON[PRIMARY]

)ON[PRIMARY]

GO

CREATE TABLE[dbo].[Student2](

[RollNo] [decimal](18,0)NULL,

[Qualification] [nvarchar](100)NULL

)ON[PRIMARY]

GO

create Function[dbo].[Getqualification](

@rollnovarchar(50))

Returnsvarchar(500)

Begin

Declare@varvarchar(500)

select @var=(select Qualification fromstudent2 where rollno=@rollno)

Return@var

--return @dt

End

call userdefine Function

selectdbo.Getqualification(rollno)fromstudent2