Question

I have 2 tables for my game script, one is a database of all the weapons ingame (db_firearms) and the other is a list of the weapons in the stores (store_firearms).

db_firearms

(the store field says whether it will appear in stores, 0 = no, 1=yes)

id    name      store
-----------------------
1     Pistol    1
2     Shotgun   1
3     Sniper    0

store_firearms

(weapon field relates to the id of the weapon in db_firearms)

id    city      weapon
-----------------------
1     Miami     1
2     Miami     2
3     New York  2 

What I want to do, is populate the store_firearms table with each MISSING weapon from the db_firearms table with store=1 (where city= $city).

What’s the best way to do a query for this in mySQL?

Answer 1

EDIT Completely botched that first try, using NOT EXISTS works.

INSERT INTO store_firearms (City, Weapon)
SELECT $city, F.Id
FROM db_firearms F        
WHERE F.Store = 1 AND NOT EXISTS (
    SELECT * FROM store_firearms WHERE City = $city AND Weapon = F.Id)

If $city were ‘New York’, this would insert ‘New York’, 1 into store_firearms