在计数中找到MAX值

Question

我的代码是

$query = "SELECT teamID, season,
    MAX(season) AS current_season,
    COUNT(DISTINCT matchID AND season=current_season) AS season_games_played,
    FROM finances
    WHERE teamID = '$_SESSION[teamID]'";

但这给了我一个错误:(

我想要做的是获得球队本赛季的比赛数量，所以current_season将是列赛季的最大值。

我的下一行代码是找出球队上赛季打了多少场比赛（MAX（赛季）-1）我假设，但这会是怎么写的？

Answer 1

最简单的方法可能是

SELECT
     season,
       COUNT(DISTINCT matchID) AS season_games_played
    FROM finances
    WHERE teamID = '$_SESSION[teamID]' /*<-- Probable SQL injection risk!*/
    GROUP BY season
    ORDER BY season DESC
    LIMIT 2;

我已经从teamID列表中删除了SELECT，因为您已经将其传递给了所有人。

我认为'$_SESSION[teamID]'是php或者什么的。请阅读有关如何避免使用该语言进行SQL注入的内容。

Answer 2

SELECT
    teamID,
    season,
    COUNT(DISTINCT matchID) AS season_games_played,
FROM finances
WHERE teamID = ?
GROUP BY 1, 2
ORDER BY 2 DESC;

第一排将是最近一个赛季，第二排将是最近一个赛季等。