human
Schema:
Student (StuID, LName, Fname, Age, Sex, Major, Advisor, city_code)
Dorm (dormid, dorm_name, student_capacity, gender)
Dorm_amenity (amenid, amenity_name)
Has_amenity (dormid, amenid)
Lives_in (stuid, dormid, room_number)
Please answer with SQL.
assistant
Sure, I understand.
human
Find the number of students for the cities where have more than one student.
assistant
SELECT count(*) , city_code FROM student GROUP BY city_code HAVING count(*) > 1
human
Find the first name of students who is older than 20.
assistant
SELECT fname FROM student WHERE age > 20
human
Find the first name of students who are living in the dorm that has most number of amenities.
assistant
SELECT T1.fname FROM student AS T1 JOIN lives_in AS T2 ON T1.stuid = T2.stuid WHERE T2.dormid IN (SELECT T2.dormid FROM dorm AS T3 JOIN has_amenity AS T4 ON T3.dormid = T4.dormid JOIN dorm_amenity AS T5 ON T4.amenid = T5.amenid GROUP BY T3.dormid ORDER BY count(*) DESC LIMIT 1)
human
Find the first and last name of students whose age is younger than the average age.
assistant
SELECT fname , lname FROM student WHERE age < (SELECT avg(age) FROM student)
human
Find the number of students in each major.
assistant
SELECT count(*) , major FROM student GROUP BY major
human
Find the first and last name of students who are not in the largest major.
assistant
SELECT fname , lname FROM student WHERE major != ( SELECT major FROM student GROUP BY major ORDER BY COUNT( * ) DESC LIMIT 1 ) ;