编辑：我已经了解了EXPLAIN。我还想确定players_teams在查询中没有索引项。我已经在我的查询中添加了一个，现在它的执行时间不到一秒。
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我对我正在尝试编写的数据库进行查询，它应该返回玩家在一个赛季中玩过的游戏数量。
我一直遇到查询问题，这些问题会返回多个不同games_id或不同team_id的条目。
我终于得到了我想要的结果，但查询现在需要3分钟来执行。
以下是目前为止（编辑过）的查询：
SELECT COUNT(DISTINCT schedule_player_status.id) AS ps_id
FROM schedule_player_status
INNER JOIN schedule ON schedule.id = schedule_player_status.ps_game_id
AND schedule.s_season_id = ".$seasonID."
AND schedule.s_datetime < NOW()
AND schedule.s_type='GAME'
INNER JOIN players_teams ON players_teams.t_team_id = schedule_player_status.ps_team_id
AND players_teams.t_season_id = ".$seasonID."
AND players_teams.t_player_id = schedule_player_status.ps_player_id
AND (players_teams.t_player_class = 'ROSTER' OR players_teams.t_player_class = 'SPARE')
WHERE schedule_player_status.ps_season_id=" . $seasonID . "
AND schedule_player_status.ps_status = 'IN'
GROUP BY schedule_player_status.ps_player_id
它是更大查询（已编辑）的一部分：
SELECT players.p_name, players.p_email, players.p_phone, players.p_dob, players.p_status, players_teams.t_player_position,
players.id AS playerID, teams.id AS teamID, teams.t_name, teams.t_div,
/*Count games played*/
(SELECT COUNT(DISTINCT schedule_player_status.id) AS gamesPlayed
FROM schedule_player_status
players_teams.t_player_class = 'SPARE')
INNER JOIN schedule ON schedule.id = schedule_player_status.ps_game_id
AND schedule.s_season_id = ".$seasonID."
AND schedule.s_datetime < NOW()
AND schedule.s_type='GAME'
INNER JOIN players_teams ON players_teams.t_team_id = schedule_player_status.ps_team_id
AND players_teams.t_season_id = ".$seasonID."
AND players_teams.t_player_id = schedule_player_status.ps_player_id
AND (players_teams.t_player_class = 'ROSTER' OR
WHERE schedule_player_status.ps_season_id=".$seasonID."
AND schedule_player_status.ps_status = 'IN'
AND schedule_player_status.ps_player_id = playerID
) AS gamesPlayed,
/*Count goals by playerID*/
SUM(players_stats.s_goals) AS s_goals,
/*Count assists by playerID*/
SUM(players_stats.s_assists) AS s_assists,
/*Count PIMs by playerID*/
SUM(players_stats.s_pims) AS s_pims
FROM `players_teams`
LEFT JOIN `players` ON players.id = players_teams.t_player_id
LEFT JOIN `players_stats` ON players_stats.s_player_id = players.id
AND players_stats.s_season_id = ".$seasonID."
AND players_stats.s_team_id = players_teams.t_team_id
LEFT JOIN `teams` ON teams.id = players_teams.t_team_id AND teams.t_season_id = " . $seasonID . "
WHERE players_teams.t_season_id = ". $seasonID ." AND (players_teams.t_player_class = 'ROSTER' OR players_teams.t_player_class = 'SPARE')
GROUP BY playerID
当我执行较大的查询时，它会在5分钟时超时。
我确定查询结构很糟糕，这是我写过的第一个查询之一。
感谢您提供的任何帮助。
马特