我在MySQL中有以下表格：
schedule
+-------------+---------------------+-----------+------------+-----------+------------+-------+-----------------+
| schedule_id | schedule_datetime | team_home | score_home | team_away | score_away | venue | schedule_status |
+-------------+---------------------+-----------+------------+-----------+------------+-------+-----------------+
| 2 | 2015-05-05 20:00:00 | 4 | 75 | 5 | 64 | 1 | 2 |
| 3 | 2015-05-05 22:00:00 | 7 | 34 | 6 | 85 | 2 | 2 |
| 4 | 2015-05-05 21:00:00 | 2 | 74 | 1 | 101 | 1 | 2 |
| 5 | 2015-05-05 17:00:00 | 8 | 96 | 3 | 85 | 2 | 2 |
| 6 | 2015-05-06 16:00:00 | 4 | 105 | 3 | 101 | 2 | 2 |
| 7 | 2015-05-06 17:30:00 | 1 | 96 | 8 | 74 | 2 | 2 |
| 8 | 2015-05-06 17:00:00 | 6 | 82 | 2 | 90 | 1 | 2 |
| 9 | 2015-05-06 19:00:00 | 5 | 76 | 7 | 101 | 1 | 2 |
| 10 | 2015-05-07 16:00:00 | 4 | 85 | 6 | 92 | 1 | 2 |
| 11 | 2015-05-07 18:00:00 | 5 | 74 | 1 | 64 | 2 | 2 |
| 12 | 2015-05-07 19:00:00 | 7 | 101 | 3 | 113 | 1 | 2 |
| 13 | 2015-05-07 21:00:00 | 2 | 75 | 8 | 105 | 2 | 2 |
| 14 | 2015-05-08 16:00:00 | 4 | 64 | 7 | 36 | 1 | 1 |
| 15 | 2015-05-08 17:30:00 | 2 | 55 | 5 | 72 | 2 | 1 |
| 16 | 2015-05-08 17:00:00 | 8 | 80 | 6 | 91 | 1 | 1 |
| 17 | 2015-05-08 21:00:00 | 3 | 115 | 1 | 96 | 2 | 1 |
| 18 | 2015-05-09 16:00:00 | 4 | 104 | 8 | 74 | 1 | 2 |
| 19 | 2015-05-09 19:00:00 | 3 | 101 | 2 | 105 | 1 | 2 |
| 20 | 2015-05-09 15:00:00 | 1 | 94 | 7 | 80 | 2 | 2 |
| 21 | 2015-05-09 18:00:00 | 6 | 101 | 5 | 110 | 2 | 2 |
| 22 | 2015-05-10 18:00:00 | 4 | 0 | 1 | 0 | 1 | 0 |
| 23 | 2015-05-10 19:30:00 | 6 | 0 | 3 | 0 | 1 | 0 |
| 24 | 2015-05-10 19:00:00 | 5 | 0 | 8 | 0 | 2 | 0 |
| 25 | 2015-05-10 21:00:00 | 7 | 0 | 2 | 0 | 2 | 0 |
| 26 | 2015-05-11 18:00:00 | 4 | 0 | 2 | 0 | 1 | 0 |
| 27 | 2015-05-11 21:00:00 | 8 | 0 | 7 | 0 | 1 | 0 |
| 28 | 2015-05-11 18:00:00 | 3 | 0 | 5 | 0 | 2 | 0 |
| 29 | 2015-05-11 21:00:00 | 1 | 0 | 6 | 0 | 2 | 0 |
+-------------+---------------------+-----------+------------+-----------+------------+-------+-----------------+
teams：
+---------+------------------------+---------------+
| team_id | team_name | team_division |
+---------+------------------------+---------------+
| 1 | New York Knicks | 1 |
| 2 | Brooklyn Nets | 1 |
| 3 | Boston Celtics | 1 |
| 4 | Philadelphia 76ers | 1 |
| 5 | Denver Nuggets | 4 |
| 6 | Minnesota Timberwolves | 4 |
| 7 | Oklahoma City Thunder | 4 |
| 8 | Portland Trail Blazers | 4 |
| 9 | Utah Jazz | 4 |
+---------+------------------------+---------------+
我尝试执行以下SQL（从以下问题修改：MySQL Volleyball Standings）：
SELECT
team_id,
COUNT(*) AS GP,
SUM(is_win) AS Wins,
SUM(NOT is_win) AS Losses
FROM
(
SELECT
team_home AS team_id,
score_home > score_away AS is_win
FROM schedule
WHERE schedule_status = 2
UNION ALL
SELECT
team_away AS team_id,
score_away > score_home AS is_win
FROM schedule
WHERE schedule_status = 2
) T1
GROUP BY team_id
ORDER BY Wins DESC, Losses ASC
我希望能够从团队表中检索团队的名称，而不是通过团队的ID进行报告。但是，使用以下代码时，我不断收到错误消息。我知道我需要加入JOIN但是我在哪里修改代码以允许我一起加入结果？
答案 0 :(得分：1)
假设您现有的查询提供了所需的结果，您只需要加入teams：
SELECT
team_name,
COUNT(*) AS GP,
SUM(is_win) AS Wins,
SUM(NOT is_win) AS Losses
FROM
(
SELECT
team_home AS team_id,
score_home > score_away AS is_win
FROM schedule
WHERE schedule_status = 2
UNION ALL
SELECT
team_away AS team_id,
score_away > score_home AS is_win
FROM schedule
WHERE schedule_status = 2
) T1
LEFT JOIN teams
ON T1.team_id = teams.team_id
GROUP BY team_name
ORDER BY Wins DESC, Losses ASC
使用LEFT，但如果团队保证在团队表中，那么您可以使用INNER。
答案 1 :(得分：1)
SELECT
T1.team_id,
teams.team_name,
COUNT(1) AS GP,
SUM(T1.is_win) AS Wins,
SUM(NOT T1.is_win) AS Losses
FROM
(
SELECT
team_home AS team_id,
score_home > score_away AS is_win
FROM schedule
WHERE schedule_status = 2
UNION ALL
SELECT
team_away AS team_id,
score_away > score_home AS is_win
FROM schedule
WHERE schedule_status = 2
) T1
INNER JOIN teams ON T1.team_id = teams.team_id
GROUP BY T1.team_id
ORDER BY Wins DESC, Losses ASC
;
一般来说，您可以将子查询视为任何其他表。我一般说，因为TEMPORARY表有一些奇怪的限制，偶尔UNIONs似乎不喜欢某些情况。