Question

我有一个游戏，表格如下：

// users
user_id | favorite_color

// games
game_id | game_name

// game_participants
id | fk_game_id | fk_user_id

我想获得特定游戏中所有用户最喜欢的颜色。我可以通过几个步骤完成此操作，例如：

// get the game.
Game game =  select * from games where game_id = 'abc';

// get each user's favorite color, one at a time.
for (participants in game) {
    select favorite_color from users where user_id = game.participants[i].id;
}

但是有没有办法在一个select语句中执行此操作？

由于

Answer 1

SELECT favorite_color
FROM games 
    INNER JOIN game_participants on games.game_id = game_participants.fk_game_id
    INNER JOIN users on users.user_id = game_participants.fk_user_id
WHERE game_id = 'abc'

Answer 2

SELECT users.favourite_color
FROM game_participants 
    INNER JOIN users ON game_participants.fk_user_id = users.user_id
WHERE fk_game_id = 'abc'

从一个语句中的不同表中获取数据？

2 个答案: