How can I use <> operator and || operator inside a stored procedure

Question

I have created an database file inside my asp.net application. Now from server explorer I tried to write a Stored procedure as follows

CREATE PROCEDURE insertData
(
@ID int,
@Name varchar(50),
    @Address varchar(50),
@bit BIT OUTPUT
)
as
begin
    declare @oldName as varchar(45)
    declare @oldAddress as varchar(45)

    set @oldName=(select EmployeeName from Employee where EmployeeName=@Name)
    set @oldAddress=(select Address from Employee where Address=@Address)

    if(@oldName <> @Name | @oldAddress <> @Address)
    insert into Employee(EmpID,EmployeeName,Address)values(@ID,@Name,@Address)
    SET @bit = 1
    END

But this is giving me an error when I am saving it like Incorrect syntax near < ..

Answer 1

There are several things wrong here

if(@oldName <> @Name | @oldAddress <> @Address)

Won't work - maybe try

if @oldName <> @Name OR @oldAddress <> @Address

Of course, this will never be true because of the way the two queries above (which could and should have just been one query assigning both variables) make sure that the variables are always equal.

Ie:

set @oldName=(select EmployeeName from Employee where EmployeeName=@Name)

What can @oldName be, if not equal to @Name ? (Okay, it could be NULL , but then <> is the wrong operator to use if NULL is what you're checking for)

I think that what you wanted to write here was:

select @oldName=EmployeeName,@oldAddress = Address from Employee where EmpID = @ID

Answer 2

You should use OR and not |

You can also do this instead of querying and checking each value separately, this will insert new row if name and/or address do not match for given empid

IF NOT EXISTS (
select * from Employee 
where EmpID = @ID AND EmployeeName = @Name AND Address = @Address)
  insert into Employee(EmpID,EmployeeName,Address)values(@ID,@Name,@Address)
  SET @bit = 1
END

Answer 3

您可以使用！=代替“ <>”，也可以使用Or代替“ |”。