Question

Customers(cust_id,name): (1,'A'),(2,'B'),(3,'C'). Orders(order_id,cust_id,amount): (1,1,200),(2,2,150),(3,1,300),(4,3,100). What does the following query return? SELECT
C.name, SUM(O.amount) AS total FROM Customers C LEFT JOIN Orders O ON
C.cust_id = O.cust_id GROUP BY
C.name HAVING SUM(O.amount) > 150;

Q: Answer-Customers(cust_id,name): (1,'A'),(2,'B'),(3,'C'). Orders(order_id,cust_id,amount): (1,1,200),(2,2,15...

Grouping by customer Customer A has orders totalling 200300 500. Customer B has orders totalling 150. Customer C has orders totalling 100. The HAVING clause keeps only groups where the total strictly exceeds 150. Customer As total 500 qualifies. Customer Bs total 150 does not satisfy 150 its exactly equal, not greater. Customer Cs total 100 also fails. So only A, 500 is returned.