CREATE FUNCTION udf_AllUserCommits(@username VARCHAR(30))
RETURNS INT
AS

BEGIN
    DECLARE @Result INT

    SET @Result = (
    SELECT
    Counts
    FROM (SELECT
    u.Username
    , COUNT(u.Username) AS Counts
    FROM Users AS u
    JOIN Commits AS c
    ON c.ContributorId = u.Id
GROUP BY u.Username) AS Temp
WHERE Username = @username)

IF @Result IS NULL
BEGIN
SET @Result = 0
END

RETURN @Result
END