WHERE meets GROUP BY - order of operations

Question

Accepted Answer

WHERE runs before GROUP BY. Only shipped orders survive the filter - Alice's 100 and Bob's 300. Then GROUP BY customer groups the two remaining rows, giving one sum per customer. If you need to filter on aggregate results (e.g. sum > 200), you need HAVING, not WHERE.

id	customer	amount	status
1	Alice	100	shipped
2	Alice	200	pending
3	Bob	300	shipped
4	Bob	400	pending