MySQL - Total count & rate of change in a single SQL query -
i'm trying extract total number of website hits plus rate of change(rate of increase/decrease) per client per city per day percentage in single sql query not able right. i've created example @ http://www.sqlfiddle.com/#!9/fd279/8 could please request assistance? try avoiding inner join, has wrong condition anyway ( t1.hitdate = t2.hitdate , t1.hitdate-1 = t2.hitdate can't satisfied): select t1.hitdate, t1.city, t1.client, sum(t1.numvisits) - ifnull((select sum(t2.numvisits) page_hits t2 t2.hitdate = t1.hitdate-1 , t2.city = t1.city , t2.client = t1.client), 0) rate_of_change page_hits t1 t1.client='c' group hitdate, city order hitdate;