針對遊戲應用的特定mysql查詢

Question

這是針對我正在開發的遊戲。 我有一個MySQL表，其中包含他們雙手各握例如武器的ID每個球員實體：

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

，我有通過ID包含每個項目的信息項目表

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

在我的服務器上解決戰鬥時，我通過id搜索每個玩家一個是攻擊者，一個是防禦者我想返回一個結果，每個玩家的武器名稱和武器屬性（即上面的damage_type）相同的行，所以我想要這樣的結果

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 

萬一plyers也可能會錯過一個或兩個武器：

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