SQL Server @@ rowcount始终返回0

Question

I have this situation here, this code actually from an old college and he is no longer with me and I'm not very familiar with stored procedure code.

SELECT @postcode = max(postcode)
FROM user
WHERE uState = @ustate                   

SELECT @postcode 'POSTCODE'             

IF @@rowcount = 0
BEGIN
    SELECT @p_status = 8
    ROLLBACK TRAN 
    PRINT 'Unable to obtain new user #.  Copy aborted'
    RETURN
END                              

UPDATE address
SET postcode   = @postcode
WHERE userID = @userID

When I run the stored procedure, it always returns rowcount = 0, even though there's a value in it.

How I know there's a value by running below query.

SELECT MAX(postcode) 
FROM user 
WHERE uState = @ustate 

Please help

Answer 1

Maybe it is a good thing that your colleague left, because the code you showed us seems to have a smell. In particular, I don't know what this line is supposed to be doing:

select @postcode 'POSTCODE'

If you wanted to assign 'POSTCODE' to @postcode , then you would use this:

select @postcode = 'POSTCODE'

But, the first select is alredy making a possible assignment, so I would just remove this line altogether:

SELECT @postcode = max(postcode)
FROM user
WHERE uState = @ustate                   

IF @@rowcount = 0
BEGIN
    SELECT @p_status = 8
    ROLLBACK TRAN
    PRINT 'Unable to obtain new user #.  Copy aborted'
    RETURN
END

@@rowcount should work with select statements, in addition to DML operations, so if that first query returns a value, then the @@rowcount should not be zero.

Answer 2

select @postcode always returns @@rowcount as 1. you can keep row count value in a variable.

I think your query should be like that.

DECLARE @RC INT

SELECT @postcode = max(postcode)
FROM user
WHERE uState = @ustate                   

SET @RC = @@ROWCOUNT

select @postcode 'POSTCODE'             

IF @RC = 0
BEGIN
    SELECT @p_status = 8
    ROLLBACK TRAN 
    PRINT 'Unable to obtain new user #.  Copy aborted'
    RETURN
END                              

UPDATE address
SET postcode   = @postcode
WHERE userID = @userID

Answer 3

Just comment this code line " select @postcode 'POSTCODE' "

Does it have a meaning for the execution of the SP ?

-- select @postcode 'POSTCODE'