Query 1

Question

I created these two tables:

CREATE TABLE `Game` (

 `GameName` varchar(30) NOT NULL,
 `GameGenre` varchar(20) NOT NULL,
 `GameDescription` varchar(500) NOT NULL,
 `GameMode` varchar(20) NOT NULL,
 PRIMARY KEY (`GameName`)
) ENGINE=InnoDB;

CREATE TABLE `GameScoreTotal` (

 `ScoreID` int(3) NOT NULL AUTO_INCREMENT,
 `GameName` varchar(30) NOT NULL,
 `OverallScoreTotal` mediumint(9) NOT NULL,
 `GraphicsTotal` mediumint(9) NOT NULL,
 `StoryTotal` mediumint(9) NOT NULL,
 `GameplayTotal` mediumint(9) NOT NULL,
 `TimeTotal` mediumint(9) NOT NULL,
 PRIMARY KEY (`ScoreID`),
  CONSTRAINT  FOREIGN KEY (`GameName`) REFERENCES `Game` (`GameName`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB;

我的问询需要从基于<条码”的十大比赛桌上收回所有信息。 HolScore Total.OverallScore Total 。

我曾尝试过问:

SELECT GameName 
FROM Game 
FULL JOIN GameScoreTotal 
    ON Game.GameName=GameScoreTotal.GameName 
ORDER BY OverallScoreTotal DESC 
LIMIT 0, 10;

SELECT Game.GameName 
FROM Game 
FULL JOIN GameScoreTotal 
    ON Game.GameName=GameScoreTotal.GameName 
ORDER BY OverallScoreTotal DESC 
LIMIT 0, 10;

Both tables have legitimate records within them.

Answer 1

Query 1

在您的第一份询问中,问题在于歌舞会和博爱会都存在野外游戏。因此,错误<代码> 实地名单上的哥伦歌舞女模棱两可:

Query 2

缩略语 FUL JOIN . rel=“nofollow noreferer”>Read here/a> 涉及MySQL JOINynex。

Try the LEFT OU JOIN between Game and GameScore Total table, this并抄录所有来自游戏桌的记录和从GameScoreTotal桌旁边的所有配对记录,如果在GameS-Total <>/em>表上没有相应的记录,则将显示NUL。

您还可以尝试NER JOIN,该编码将只记录两个表格之间的对应记录。

Script:

SELECT Game.GameName FROM Game LEFT OUTER JOIN GameScoreTotal ON Game.GameName=GameScoreTotal.GameName ORDER BY OverallScoreTotal DESC LIMIT 0, 10;

Query 1

Query 2

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