SQL幫助，不能得到所需的輸出，連接

我有這個疑問：SQL幫助，不能得到所需的輸出，連接

SELECT 
    t1.team_flag AS flag_1, 
    t2.team_flag AS flag_2, 
    t1.team_name AS team_name_1, 
    t2.team_name AS team_name_2, 
    t1.team_id AS team_id_1, 
    t2.team_id AS team_id_2, 
    games.game_id, 
    games.game_team_1, 
    games.game_team_2, 
    games.game_time, 
    games.game_day, 
    games.game_location, 
    games.game_group, 
    games.game_active, 
    location_id_to_names.location_id, 
    location_id_to_names.location_name 
FROM games 
    LEFT JOIN teams t1 ON t1.team_id = game_team_1 
    LEFT JOIN teams t2 ON t2.team_id = game_team_2 
    LEFT JOIN location_id_to_names ON games.game_location = location_id_to_names.location_id 
ORDER BY games.game_day

與正確的所有球隊的名字將返回所有的遊戲，不過，我現在想用一個特定的選擇只有一場比賽ID，這是行不通的：

SELECT 
    t1.team_flag AS flag_1, 
    t2.team_flag AS flag_2, 
    t1.team_name AS team_name_1, 
    t2.team_name AS team_name_2, 
    t1.team_id AS team_id_1, 
    t2.team_id AS team_id_2, 
    games.game_id, 
    games.game_team_1, 
    games.game_team_2, 
    games.game_time, 
    games.game_day, 
    games.game_location, 
    games.game_group, 
    games.game_active, 
    location_id_to_names.location_id, 
    location_id_to_names.location_name 
FROM games 
    LEFT JOIN teams t1 ON t1.team_id = game_team_1 AND games.game_id = :game_id 
    LEFT JOIN teams t2 ON t2.team_id = game_team_2 
    LEFT JOIN location_id_to_names ON games.game_location = location_id_to_names.location_id 
ORDER BY games.game_day

（：game_id）被PDO解析。

這是我得到的輸出：

enter image description here ID是突出顯示的行是正確的，但它不是第一排，我需要這是第一排，因爲我想將搜索限制爲1個結果，所以我不希望行中填充空值。

完成這件事的最好方法是什麼？

來源

2014-06-05 aabreu

考慮提供適當的DDLs（和/或一個sqlfiddle）與期望的結果集合在一起。這就是說，你可以嘗試按「flag_1 IS NULL」排序 – Strawberry

我不太明白。您必須添加一個「LIMIT」子句才能獲得1個結果;但是如果你只想要你的例子的第二行，你就必須考慮一個'WHERE field IS NOT NULL'子句。 –

從你的連接中刪除'LEFT' - 你不需要它 - 你需要的只是一個直接連接。 –

移動games.game_id =：game_id到WHERE語句

SELECT 
    t1.team_flag AS flag_1, 
    t2.team_flag AS flag_2, 
    t1.team_name AS team_name_1, 
    t2.team_name AS team_name_2, 
    t1.team_id AS team_id_1, 
    t2.team_id AS team_id_2, 
    games.game_id, 
    games.game_team_1, 
    games.game_team_2, 
    games.game_time, 
    games.game_day, 
    games.game_location, 
    games.game_group, 
    games.game_active, 
    location_id_to_names.location_id, 
    location_id_to_names.location_name 
FROM games 
    LEFT JOIN teams t1 ON t1.team_id = game_team_1 
    LEFT JOIN teams t2 ON t2.team_id = game_team_2 
    LEFT JOIN location_id_to_names ON games.game_location = location_id_to_names.location_id 
WHERE 
    games.game_id = :game_id 
ORDER BY games.game_day

來源

2014-06-05 09:02:42 fonfi

從您的加入LEFT並留在原地簡單JOIN：

SELECT 
    t1.team_flag AS flag_1, 
    t2.team_flag AS flag_2, 
    t1.team_name AS team_name_1, 
    t2.team_name AS team_name_2, 
    t1.team_id AS team_id_1, 
    t2.team_id AS team_id_2, 
    games.game_id, 
    games.game_team_1, 
    games.game_team_2, 
    games.game_time, 
    games.game_day, 
    games.game_location, 
    games.game_group, 
    games.game_active, 
    location_id_to_names.location_id, 
    location_id_to_names.location_name 
FROM games 
    LEFT JOIN teams t1 ON t1.team_id = game_team_1 AND games.game_id = :game_id 
    LEFT JOIN teams t2 ON t2.team_id = game_team_2 
    LEFT JOIN location_id_to_names ON games.game_location = location_id_to_names.location_id 
ORDER BY games.game_day

的LEFT部分負責加盟的行你想要與同一團隊的所有其他行。

來源

2014-06-05 09:17:49

SQL幫助，不能得到所需的輸出，連接

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