/****** Object: UserDefinedFunction [dbo].[FuncCompareImage] Script Date: 2016-09-01 11:18:53 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER FUNCTION [dbo].[FuncCompareImage] ( @a1 IMAGE, @a2 IMAGE )
RETURNS INT
-- if match, return 1
AS
BEGIN
DECLARE @n INT ,
@i INT ,
@j INT;
DECLARE @b1 VARBINARY(8000) ,
@b2 VARBINARY(8000);
SET @n = 1;
IF DATALENGTH(@a1) <> DATALENGTH(@a2) -- different length
SET @n = 0;
ELSE
BEGIN
SET @i = 0;
SET @j = ( DATALENGTH(@a1) - 1 ) / 8000 + 1;
WHILE @i <= @j
BEGIN
SET @b1 = SUBSTRING(@a1, @i * 8000 + 1,
CASE @i
WHEN @j
THEN DATALENGTH(@a1) % 8000
ELSE 8000
END);
SET @b2 = SUBSTRING(@a2, @i * 8000 + 1,
CASE @i
WHEN @j
THEN DATALENGTH(@a2) % 8000
ELSE 8000
END);
IF @b1 <> @b2
BEGIN
SET @n = 0;
BREAK;
END;
SET @i = @i + 1;
END;
END;
RETURN(@n);
END;