Question

Right now, I have

SELECT gp_id FROM gp.keywords  WHERE keyword_id = 15  AND (SELECT practice_link FROM gp.practices       WHERE practice_link IS NOT NULL       AND id = gp_id) 

This does not provide a syntax error, however for values where it should return row(s), it just returns 0 rows.

What I’m trying to do is get the gp_id from gp.keywords where the the keywords table keyword_id column is a specific value and the practice_link is the practices table corresponds to the gp_id that I have, which is stored in the id column of that table.

Answer 1

I’m not even sure that is valid SQL, so I’m surprised it is working at all:

SELECT gp_id FROM gp.keywords WHERE keyword_id = 15     AND (SELECT practice_link FROM gp.practices WHERE practice_link IS NOT NULL AND id = gp_id) 

How about this instead:

SELECT kw.gp_id, p.practice_link FROM gp.keywords AS kw INNER JOIN gp.practices AS p     ON p.id = kw.gp_id WHERE kw.keyword_id = 15 

I would steer clear of implicit joins as in the other examples. It only leads to tears later.