Question

I have the following table:

ThisCategoryID int   IDENTITY, AUTO_INCREMENT
Title          text
Type           text
CategoryID     int   ALLOW NULLS
IsActive       bit
OrderIndex     int   ALLOW NULLS

with this data:

ThisCategoryID  Title    Type          CategoryID  IsActive  OrderIndex
0               Lunch    Menu Section  NULL        True      3
2               Dessert  Menu Section  NULL        True      1
3               Banh Mi  Food Item     0           True      4

and the following stored procedure:

ALTER PROCEDURE [dbo].[sp_new_category]
    @Title text,
    @Type text,
    @CategoryID int = null,
    @IsActive bit, 
    @OrderIndex int = null
AS
    DECLARE @Identity int
    IF (SELECT count(*) FROM Category WHERE difference(title, @title) = 4) > 0
    BEGIN
        INSERT INTO Category (Title, Type, CategoryID, IsActive, OrderIndex) VALUES (@Title, @Type, @CategoryID, @IsActive, @OrderIndex)
        SET @Identity = scope_identity()
    END
    ELSE
    BEGIN
        SET @Identity = -1
    END
    SELECT @Identity AS ID
    RETURN @Identity

There is no item in the table with the title “Snack”, yet the sp_new_category yields -1, every time I run it with the following parameters:

 @Title: Snack
 @Type: Menu Section
 @CategoryID: NULL
 @IsActive: True
 @OrderIndex: NULL

Can someone explain to me why that is?

Answer 1

I believe your intent for the following conditional is to check if someone is trying enter an already existing item by Title (matched with SOUNDEX):

IF (SELECT count(*) FROM Category WHERE difference(title, @title) = 4) > 0

However, the way the conditional is written, you will only add items if they are similar. Try this instead:

DECLARE @Identity int
IF (SELECT count(*) FROM Category WHERE difference(title, @title) = 4) > 0
BEGIN
    SET @Identity = -1
END
ELSE
BEGIN
    INSERT INTO Category (Title, Type, CategoryID, IsActive, OrderIndex) VALUES (@Title, @Type, @CategoryID, @IsActive, @OrderIndex)
    SET @Identity = scope_identity()
END
SELECT @Identity AS ID
RETURN @Identity