Question

我想知道“TX”中的哪支球队没有参加比赛。（换句话说，我在寻找许多表中没有相关记录的记录选择。）

这是SQL：

（或者，如果您更喜欢sql小提琴，请访问：http://sqlfiddle.com/#!2/14106）

CREATE  TABLE `Team` (
  `ID` INT NOT NULL AUTO_INCREMENT ,
  `Name` VARCHAR(45) NULL ,
  `State` VARCHAR(45) NULL ,
  PRIMARY KEY (`ID`) );

CREATE  TABLE `Games` (
  `ID` INT NOT NULL AUTO_INCREMENT,
  `Team_ID` INT NULL ,
  `Game_Day` DATE NULL ,
  PRIMARY KEY (`ID`) );

    INSERT INTO `Team` (`Name`, `State`) VALUES ('Rams', 'TX');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Rockets', 'OK');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Bombers', 'TX');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Yellow Jackets', 'NV');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Wildcats', 'CT');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Miners', 'CO');
    INSERT INTO `Team` (`Name`, `State`) VALUES ('Bolts', 'TX');

    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('2', '2013-03-16');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('2', '2013-01-01');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('3', '2013-04-16');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('5', '2013-02-02');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('4', '2013-02-12');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('6', '2013-01-09');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('6', '2013-01-01');
    INSERT INTO `Games` (`Team_ID`, `Game_Day`) VALUES ('3', '2013-05-01');

我应该得到结果：

ID     Name    
1      Rams
7      Bolts

Answer 1

使用外部联接，仅选择不匹配的行

SELECT t.*
FROM TEAM t
LEFT JOIN GAMES g ON g.team_id = t.id
WHERE t.state = 'TX'
AND g.team_id is null -- return only rows that *don't* join

这在SQL Fiddle

中运行

请注意，使用连接将超出子查询方法，尤其是在数据集变大时。

Answer 2

SELECT `ID`, `Name` FROM `TEAM` 
  WHERE `ID` NOT IN (SELECT DISTINCT(`Team_ID`) from `Games`) 
  AND `State` = 'TX';

SqlFiddle here。

Answer 3

您也可以左键加入Games表，并过滤掉没有相应Games行的位置。当表有很多行时，这通常比NOT IN更快：

SELECT Team.ID, Team.Name
FROM Team
LEFT JOIN Games ON Team.ID = Games.Team_ID
WHERE Team.State = 'TX' AND Games.ID IS NULL;

如果Games行中没有Teams行，则Games.ID列在结果中将为空，因此如果您对Games.ID IS NULL进行过滤你将获得团队没有游戏的所有行。

有一个SQL小提琴here。

Answer 4

希望这会有所帮助。

select t.ID,t.NAME
FROM Team t
WHERE t.state = 'TX'
AND t.id NOT IN (SELECT g.TEAM_ID FROM Games g)

获取没有相关记录的记录列表MySQL

4 个答案: