How to compare software versions using SQL Server?

Question

When trying to compare software versions 5.12 to 5.8, version 5.12 is newer, however mathematically 5.12 is less than 5.8. How would I compare the two versions so that a new

Answer 1

The solution that was implemented:

CREATE FUNCTION [dbo].[version_compare]
(
    @v1 VARCHAR(5), @v2 VARCHAR(5)
)
RETURNS tinyint
AS
BEGIN
    DECLARE @v1_int tinyint, @v1_frc tinyint, 
            @v2_int tinyint, @v2_frc tinyint, 
            @ResultVar tinyint

    SET @ResultVar = 0

    SET @v1_int = CONVERT(tinyint, LEFT(@v1, CHARINDEX('.', @v1) - 1))
    SET @v1_frc = CONVERT(tinyint, RIGHT(@v1, LEN(@v1) - CHARINDEX('.', @v1)))
    SET @v2_int = CONVERT(tinyint, LEFT(@v2, CHARINDEX('.', @v2) - 1))
    SET @v2_frc = CONVERT(tinyint, RIGHT(@v2, LEN(@v2) - CHARINDEX('.', @v2)))

    SELECT @ResultVar = CASE
        WHEN @v2_int > @v1_int THEN 2
        WHEN @v1_int > @v2_int THEN 1
        WHEN @v2_frc > @v1_frc THEN 2
        WHEN @v1_frc > @v2_frc THEN 1
    ELSE 0 END

    -- Return the result of the function
    RETURN @ResultVar
END
GO