NERS 421 มีการบรรยายกี่ครั้งต่อสัปดาห์ ?ไม่จำเป็นต้องใช้ตารางทั้งหมด
NERS 421 has how many lectures per week ?It is not neccessary to use all the tables.
 requirement:  requirement_id [ int]  requirement [ varchar]  college [ varchar] 
SELECT (SELECT SUM(CASE WHEN DERIVED_TABLEalias0.FRIDAY = 'Y' THEN 1 ELSE 0 END) + SUM(CASE WHEN DERIVED_TABLEalias0.MONDAY = 'Y' THEN 1 ELSE 0 END) + SUM(CASE WHEN DERIVED_TABLEalias0.SATURDAY = 'Y' THEN 1 ELSE 0 END) + SUM(CASE WHEN DERIVED_TABLEalias0.SUNDAY = 'Y' THEN 1 ELSE 0 END) + SUM(CASE WHEN DERIVED_TABLEalias0.THURSDAY = 'Y' THEN 1 ELSE 0 END) + SUM(CASE WHEN DERIVED_TABLEalias0.TUESDAY = 'Y' THEN 1 ELSE 0 END) + DERIVED_FIELDalias6 FROM (SELECT SUM(CASE WHEN DERIVED_TABLEalias0.FRIDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.MONDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.SATURDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.SUNDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.THURSDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.TUESDAY = 'Y' THEN 1 ELSE 0 END), SUM(CASE WHEN DERIVED_TABLEalias0.WEDNESDAY = 'Y' THEN 1 ELSE 0 END), COURSE_OFFERING, SEMESTER WHERE COURSEalias0.COURSE_ID = COURSE_OFFERING.COURSE_ID AND COURSEalias0.DEPARTMENT = 'NERS' AND COURSEalias0.NUMBER = 421 AND SEMESTER.SEMESTER = 'WN' AND SEMESTER.SEMESTER_ID = COURSE_OFFERING.SEMESTER AND SEMESTER.YEAR = 2016 LIMIT 1) AS DERIVED_TABLEalias0) AS DERIVED_TABLEalias1