MySQL子查询没有给我MAX或ORDER BY LIMIT 1的最大值

我的MySQL查询有问题。其子查询未给出last.id的最高值

我也尝试过这种方法，但不起作用：

SELECT rounds.winners, rounds.losers
FROM players
INNER JOIN teams ON teams.id = players.ilmo_id
INNER JOIN status AS first ON first.id = players.status_id
LEFT JOIN matches ON matches.chart_id = 12
  AND matches.id = (
    SELECT  MAX(last.id)
    FROM    matches AS last
    WHERE   (last.player1_id = players.id
            OR last.player2_id = players.id
            OR last.player3_id = players.id
            OR last.player4_id = players.id)
        )

 JOIN charts ON charts.id = matches.chart_id
 JOIN places ON charts.template_id = places.template_id AND places.id = matches.place_id
 JOIN templates ON places.template_id = templates.id
 JOIN rounds ON places.round_id = rounds.id
 WHERE players.comp_id = 12

编辑：

这是最新的版本，看起来还可以

SELECT rounds.winners, rounds.losers
FROM players
INNER JOIN teams ON teams.id = players.ilmo_id
INNER JOIN status AS first ON first.id = players.status_id
LEFT JOIN matches ON matches.chart_id = 12
  AND matches.id = (
    SELECT  last.id
    FROM    matches AS last
    WHERE   last.chart_id = 12 /* modified */
            AND (last.player1_id = players.id
            OR last.player2_id = players.id
            OR last.player3_id = players.id
            OR last.player4_id = players.id)
            ORDER BY last.place_id DESC /* modified */
            LIMIT 1
        )

 JOIN charts ON charts.id = matches.chart_id
 JOIN places ON charts.template_id = places.template_id AND places.id = matches.place_id
 JOIN templates ON places.template_id = templates.id
 JOIN rounds ON places.round_id = rounds.id
 WHERE players.comp_id = 12

---

几乎可以肯定的是，以前有过数千次的提问和回答，但如果仍在挣扎，看看你加入比赛的目的是什么？on子句看起来更像where子句的条件。您正在加入chart_id=12且是最高id的匹配，但在子查询中，您没有引用chart_id。它返回所有chart_id中的最高id。因此，如果最高ID行没有chart\u ID=12，on子句将不匹配。@现在我的子查询有WHERE last.chart\u ID=12和last.player1\u ID。。。好吗？是的，我现在明白了。我认为您不需要匹配。打开后立即使用chart_id=12。这是多余的，因为它是在子查询中处理的。您认为maxlast.id比使用order by和limit 1更好吗？只是因为它是跨平台的标准。但我会使用提供最佳性能的语法。

SELECT rounds.winners, rounds.losers
FROM players
INNER JOIN teams ON teams.id = players.ilmo_id
INNER JOIN status AS first ON first.id = players.status_id
LEFT JOIN matches ON matches.chart_id = 12
  AND matches.id = (
    SELECT  last.id
    FROM    matches AS last
    WHERE   last.chart_id = 12 /* modified */
            AND (last.player1_id = players.id
            OR last.player2_id = players.id
            OR last.player3_id = players.id
            OR last.player4_id = players.id)
            ORDER BY last.place_id DESC /* modified */
            LIMIT 1
        )

 JOIN charts ON charts.id = matches.chart_id
 JOIN places ON charts.template_id = places.template_id AND places.id = matches.place_id
 JOIN templates ON places.template_id = templates.id
 JOIN rounds ON places.round_id = rounds.id
 WHERE players.comp_id = 12

SELECT rounds.winners, rounds.losers
FROM players
INNER JOIN teams ON teams.id = players.ilmo_id
INNER JOIN status AS first ON first.id = players.status_id
LEFT JOIN matches ON matches.id = (
    SELECT  max(last.id)
    FROM    matches AS last
    WHERE   last.chart_id = 12 /* modified */
            AND (last.player1_id = players.id
            OR last.player2_id = players.id
            OR last.player3_id = players.id
            OR last.player4_id = players.id)
        )
 JOIN charts ON charts.id = matches.chart_id
 JOIN places ON charts.template_id = places.template_id AND places.id = matches.place_id
 JOIN templates ON places.template_id = templates.id
 JOIN rounds ON places.round_id = rounds.id
 WHERE players.comp_id = 12