SUM() based on a different condition to the SELECT

Hi is there a way that I can do the SUM(total_points) based on a different condition to the rest of the SELECT statement, so I want the SUM(total_points) for every row which is <= to $chosentrack? but the rest of the conditions of the SELECT statement to be what they are below. I need them to all be returned together..as I am populating a league table.

Thanks a lot for any help.

SELECT
    members.member_id,
    members.teamname,
    SUM(total_points) as total_points,
    total_points as last_race_points 
FROM
    members,
    members_leagues,
    member_results 
WHERE
    members.member_id = members_leagues.member_id 
    AND members_leagues.league_id开发者_如何学运维 = '$chosenleague' 
    AND member_results.track_id = '$chosentrack' 
    AND members_leagues.start_race = '$chosentrack' 
    AND member_results.member_id = members_leagues.member_id
GROUP BY
    members.member_id 
ORDER BY
    member_results.total_points DESC,
    last_race_points DESC, 
    members.teamname DESC

You can also put the sum inside a case statement, where the case evaluates the other condition, and then only sum thoses records where the condition is true...

  SELECT m.member_id, m.teamname, 
    Sum(Case When r.track_Id = '$chosentrack' 
         Then total_points Else 0 End) TotalChosenTrackPoints,
    Sum(Case When r.track_Id < '$chosentrack' 
         Then total_points Else 0 End) TotalLessThanChosenTrackPoints, 
    total_points as last_race_points  
 FROM members m
    Join members_leagues l
       On l.member_id = m.member_id  
    Join member_results r
       On r.member_id = m.member_id
 Where l.league_id = '$chosenleague'
    And l.start_race = '$chosentrack'
 Group By m.member_id
 Order By r.total_points Desc, 
     last_race_points  Desc, m.TeamName Desc  

SELECT ... 
SUM(CASE
WHEN track_id <= [your_value] THEN total_points
ELSE 0
END
) AS total_points, .... 

Do the sum as a subselect, making sure that you select an additional column (don't forget to group by that column) and join the result of this subselect to the main query using the common field.

Template:

Select col1, 
col2 as t,x.thesum
From table t left join 
( select sum(colx) as thesum, col1 from t where ...
 Group by col1) x on t.col1=x.col1
 Where ....