存储过程拒绝插入数据

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

Answer 2

SELECT difference('Snack', 'Lunch')
UNION SELECT difference('Snack', 'Dessert')
UNION SELECT difference('Snack', 'Banh Mi')

3
1
2

None of your differences ever equal 4, so your insert is never run, so @identity will always be -1

difference is the difference in SOUNDEX encodings for text, which is an archaic hash for English names. It is not suitable for foreign words. If you tell us what you think you are accomplishing by using it, we may be able to help you.

Answer 3

Am I missing something?

The IF statement is false so he goes to the ELSE and puts SET @Identity = -1 . So it'll return -1 .