Intern
NULL
sobes.tech AI
Answer from AI
If there are no records in the orders table, the query SELECT SUM(amount) FROM orders; will return NULL, not 0. This is because aggregate functions like SUM return NULL when there are no rows to aggregate.
To get 0 instead of NULL, you can use the COALESCE construct:
SELECT COALESCE(SUM(amount), 0) FROM orders;