Question

我正在使用它：

SELECT res.*, rac.*, u.*, t.*, c.*
FROM Results res
INNER JOIN Races rac USING (RaceID)
INNER JOIN Users u USING (UserID)
INNER JOIN Teams t USING (TeamID)
INNER JOIN Cars c USING (CarID)
WHERE res.SeasonNumber = '$SeasonNumber' AND res.LeagueID = '$LeagueID' AND Position = '1' AND ResultConfirmed = '1'
ORDER BY Position ASC

哪个工作正常，但我已经意识到我需要将CarID添加到Results表中，但是当我添加它时，它会给我一个错误，即该字段是不明确的。我想做的是从Car表中获取汽车名称，其中CarID加入汽车和结果。当我尝试这样做时：

SELECT res.*, rac.*, u.*, t.*, c.*
FROM Results res
INNER JOIN Races rac USING (RaceID)
INNER JOIN Users u USING (UserID)
INNER JOIN Teams t USING (TeamID)
INNER JOIN Cars c USING (res.CarID)
WHERE res.SeasonNumber = '$SeasonNumber' AND res.LeagueID = '$LeagueID' AND Position = '1' AND ResultConfirmed = '1'
ORDER BY Position ASC

我收到以下错误：

您的SQL语法有错误;检查手册对应于您的MySQL服务器版本，以便使用正确的语法靠近＆＃39; .CarID）WHERE res.SeasonNumber =＆＃39; 1＆＃39; AND res.LeagueID =＆＃39; 1＆＃39;和位置=＆＃39; 1＆＃39; ＆＃39;在第6行

Answer 1

您可以将USING子句替换为ON()，在USING()子句中，我猜您添加的列名与您要加入的其他表中的列名相同，但您将联接放在最后并使用别名res mysql将不允许此

INNER JOIN Cars c ON(res.CarID =c.CarID)

如果您需要使用USING()子句，则需要调整联接展示位置，例如

SELECT res.*, rac.*, u.*, t.*, c.*
FROM 
Cars c
INNER JOIN Results res USING (CarID)
INNER JOIN Races rac USING (RaceID)
INNER JOIN Users u USING (UserID)
INNER JOIN Teams t USING (TeamID)
WHERE res.SeasonNumber = '$SeasonNumber' AND res.LeagueID = '$LeagueID' AND Position = '1' AND ResultConfirmed = '1'
ORDER BY Position ASC

但ON()子句更具可读性

从多个表中加载详细信息

1 个答案: