SELECT SUM(count)
FROM (SELECT (`c1fa` != "") + (`c2fa` != "") + (`c3fa` != "") + (`c4fa` != "") + (`c5fa` != "") + (`c6fa` != "") + (`c7fa` != "")
 + (`c8fa` != "") AS `count` FROM `schedule` WHERE `day` > '1107' ORDER BY `day` ASC))

MySQL returned:  

#1248 - Every derived table must have its own alias