MySQL using BETWEEN comparison with NULL

Question

I have a query with a where condition like so:

WHERE A.event_date BETWEEN B.start_date AND B.end_date

The complexity is that if B.sta

Answer 1

IFNULL might help out here:

WHERE A.event_date BETWEEN IFNULL(B.start_date,"1900-01-01") 
                   AND IFNULL(B.end_date,now());