HAVING and UNKNOWN

Question

HAVING and UNKNOWN

Accepted Answer

HAVING follows the same 'accept TRUE' rule as WHERE. Bob's SUM(amount) is NULL because both of his rows are NULL, and NULL > 100 is UNKNOWN - not TRUE. So Bob's group is excluded. Alice's total is 300, which is greater than 100 (TRUE), so her group is included. The NULL-exclusion rule applies to HAVING filters exactly the same way it applies to WHERE.

rep	amount
Alice	100
Alice	200
Bob	NULL
Bob	NULL

Alice	300
Bob	NULL

Alice	300
Bob	0

Alice	300
Bob	200