Question

i have two tables. a user table and a photo table. IF a user uploads photo’s, they have the option of specifying only one as a ‘primary’ profile photo (enforced on the front-end).

tbl_users
---------
user_id
username

tbl_photos
---------
photo_id
user_id
is_primary (bit)
file_name

when i’m querying a list of users on a user search, for example, i want their chosen primary photo to display. however, if there are no linked records in the photo table or there are, but none are marked primary, I still want to return the users record and perhaps NULL or some other value for the file_name.

how would I accomplish this?

ps. i’m currently doing this through two separate calls to the database, but want this done in one call for efficiency.

Answer 1

Depending on what DB you use this works (userid2query being the id of the user you want to retrieve):

SELECT u.user_id, u.username, p.photo_id, p.file_name 
from tbl_users u
left outer join tbl_photos p on u.user_id = p.user_id and p.is_primary = 1
where u.user_id = userid2query

It returns the user information and the primary photo information – IF no primary photo or no photo at all it stills returns the user information but returns NULL for the photo information columns.