Question

This is for a game I’m developing.
I have a MySQL table with each player entity that contains the id of the weapon they hold in each hand for example:

player id, playername, rhand, lhand,
1          Guy         1      2
2          OtherGuy    3      2

and I have an items table containing information about each item by id

item  name   damage_type
1     hammer crush
2     shield none
3     sword  slash

when resolving combat on my server I search for each player by id one is the attacker and one is the defender I would like to return a result with each players weapon name and perhaps a property of the weapon (i.e. damage_type above) on the same line so I’d like results like this

player id playername rhand lhand   rhand_damage_type lhand_damage_type
1         Guy        hammer shield crush             none
2         OtherGuy   sword  shield slash             none

Answer 1

SELECT p.player_id, p.player_name, w1.name, w2.name, w1.damage_type, w2.damage_type 
FROM players p, weapons w1, weapons w2 
WHERE p.player_id = attackerId OR p.player_id=defenderId
AND p.rhand = w1.item 
AND p.lhand = w2.item

In case the plyers might also miss one or both weapons:

SELECT DISTINCT player_id, player_name, w1.name, w2.name, w1.damage_type, w2.damage_type 
FROM 
(SELECT player_id, player_name, name, damage_type 
 FROM players LEFT JOIN weapons on rhand = w1.item 
 WHERE p.player_id = attackerId OR p.player_id=defenderId) as w1,
(SELECT player_id, player_name, name, damage_type 
 FROM players LEFT JOIN weapons on lhand = w2.item 
 WHERE p.player_id = attackerId OR p.player_id=defenderId) as w2
 Were w1.player_id = w2.player_id