SELECT count(*) ,  T3.school_code FROM CLASS AS T1 JOIN course AS T2 ON T1.crs_code  =  T2.crs_code JOIN department AS T3 ON T2.dept_code  =  T3.dept_code GROUP BY T3.school_code
How many classes exist for each school?
SELECT count ( * ) , T3.school_code FROM CLASS AS T1 JOIN course AS T2 ON T1.crs_code = T2.crs_code JOIN department AS T3 ON T2.dept_code = T3.dept_code GROUP BY T3.school_code
select count ( * ) , t3 . school_code from class as t1 join course as t2 on t1 . crs_code = t2 . crs_code join department as t3 on t2 . dept_code = t3 . dept_code group by t3 . school_code
How many classes exist for each school ?