sql query for days until next birthday?

[eluser]sophistry[/eluser]
ok, major logic flaw in the previous version... comparing month number and day number is the wrong approach - it doesn't make sense and it gives wrong results.

here is the final version (just sending the SQL select since the other parts were fine):

Code:

$this->db->select("IF (
DATEDIFF( CONCAT_WS('-',YEAR($Ymd),MONTH(datetime_start),DAYOFMONTH(datetime_start)),$Ymd) >= 0,
    DATEDIFF( CONCAT_WS('-',YEAR($Ymd),MONTH(datetime_start),DAYOFMONTH(datetime_start)),$Ymd),
    DATEDIFF( CONCAT_WS('-',YEAR($Ymd)+1,MONTH(datetime_start),DAYOFMONTH(datetime_start)),$Ymd)
)
AS days_until_event", FALSE);