Question

To simplify the problem down for the question, I have a listings table and a listings_featured table. The main listings tables holds the main data for all listings but the listings_featured table holds data for only listings which are featured.

I want to display listings ordered by whether they are featured or not first, meaning the rows which have a match when doing a LEFT or RIGHT JOIN should come first. How would I go about doing this with just one query rather than two?

EDIT

Also, is it possible to add a WHERE condition to the query that only applies to the joined records? For example, out of the featured listings, I only want the ones which have the condition WHERE featured_end_date > now() – this should only apply to the joined records. This is because the duration for which a listing is featured will be different to the actual expiry date of the listing.

Answer 1

SELECT l.*
FROM listings l
    LEFT JOIN listings_featured lf ON lf.lid = l.lid
WHERE lf.lid IS NULL OR lf.featured_end_date > now()
ORDER BY lf.lid IS NULL

lf.lid IS NULL is FALSE for all featured listings so while sorting they get put before other listings.

EDIT

Added WHERE condition