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Databases

Muhittin Palamutçu
Muhittin Palamutçu
1,890 Points
Posted by Muhittin Palamutçu
Muhittin Palamutçu
1,890 Points

I need some help for my Sql Query

Student(id(key),name) Professor(id,name,deperment) Course(number(key),instructorID,title,credits,roomNumber) Enroll(StudentID(key),courseNumber(key) Room(number(key),capacity)

I need to find course number and their titles that have more than 40 students enrolled?

SELECT C.number,C.titles FROM Course C,Enroll E WHERE C.number=E.courseNumber AND E.count(StudentID)>40;

I wrote something like that but ı know it's false. If you help me ı will be pleased.

2 Answers

KRIS NIKOLAISEN
KRIS NIKOLAISEN
54,971 Points

Try this:

SELECT enroll.courseNumber, course.title FROM course, enroll WHERE course.number = enroll.courseNumber GROUP BY enroll.courseNumber, course.title HAVING ( ( COUNT( enroll.studentID ) > 40 ) )
Steven Parker
Steven Parker
231,248 Points
Steven Parker
Steven Parker
231,248 Points

It looks like you're getting close, here's a couple of hints:

  • a GROUP BY might be handy when counting things that have something in common
  • another way to filter when using grouping is with the HAVING keyword