SQL Server stored procedure EAN code validation

Question

I need to write a stored procedure or funtion to validate the insert of EAN13 code in SQL Server.

Can anyone help me?

Answer 1

Resolved,

I created a function for validation:

CREATE FUNCTION [sp_ean](@Ean varchar(max)) RETURNS INT AS
BEGIN
    DECLARE @Factor INT
    DECLARE @Sum INT
    DECLARE @Len INT
    DECLARE @CC INT
    DECLARE @CA INT
    DECLARE @Result NVARCHAR(MAX)

    SET @Len = LEN(@Ean)
    SET @Sum = 0
    SET @Factor = 3

    IF @Len = 14 OR @Len = 13 OR @Len = 12 OR @Len = 8 
        BEGIN
            WHILE @Len > 0 
                BEGIN
                    IF @Len  13
                        BEGIN
                            SET @Sum = @Sum + SUBSTRING(@Ean,@Len,1) * @Factor
                            SET @Factor = 4 - @Factor
                        END
                    SET @Len = @Len - 1
                END

            SET @CC = ((1000 - @Sum) % 10)
            SET @CA = SUBSTRING(@Ean,LEN(@Ean),1)

            IF  @CC = @CA
                BEGIN
                    SET @Result = 0
                END
            ELSE
                BEGIN
                    SET @Result = 1
                END
        END
    ELSE
        BEGIN
            SET @Result = 1
        END
    RETURN (@Result)
    END

Result: 0 to true or 1 to false

Thanks!