Update table with SUM from another table

Question

I am trying to what I thought was going to be a simple update of a table with the sum from another table, but for some reason, it is only updating one row. Here is what the

Answer 1

UPDATE playercareer c
INNER JOIN (
  SELECT gameplayer, SUM(points) as total
  FROM games
  GROUP BY gameplayer
) x ON c.playercareername = x.gameplayer
SET c.playercareerpoints = x.total