having

HAVING — guruhlar uchun WHERE. U GROUP BY dan keyin ishlaydi va agregatlar bilan shart qo‘yadi.

SELECT faculty, AVG(grade) AS avg_grade
FROM students
GROUP BY faculty
HAVING AVG(grade) >= 4;          -- o‘rtachasi 4 dan yuqori fakultetlar

SELECT customer_id FROM orders
GROUP BY customer_id
HAVING COUNT(*) >= 3;            -- kamida 3 ta buyurtma

Farqi: WHERE alohida qatorlarni guruhlashdan oldin filtrlaydi, HAVING tayyor guruhlarni.