CODEWITHSUNDEEP
sqlsqlite
Benj Gonzales
Benj Gonzales

Reputation: 57

SQL COUNT get zero

SELECT COUNT(*) totalStudent,
c.* 
FROM classroom c 
INNER JOIN student s
ON c.classID = s.classID 
GROUP BY c.classID

How to get zero in totalStudent? if student empty inside the classroom.

Upvotes: 0

Views: 280

Answers (1)

Gordon Linoff
Gordon Linoff

Reputation: 1270401

I am interpreting your question as: "Some classes have no students. How do I include these?" If this is correct, then the key is left join:

SELECT c.classId, COUNT(s.classId)
FROM classroom c LEFT JOIN
     student s
     ON c.classid = s.classid
GROUP BY c.classId;

Upvotes: 1

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