MySQL - SUM IF

 SELECT

    ball, 

    SUM(IF(color = 'blue', count, 0)) AS 'Total Blue'

    SUM(IF(color = 'red', count, 0)) AS 'Total Red'

 FROM t1

 GROUP BY ball

출처 : http://stackoverflow.com/questions/12169256/mysql-subquery-using-sum-where-group-by