4

我想知道“TX”中哪支球队没有打过比赛。（换句话说，我正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 fiddle 在这里：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
4

4 回答 4

6

Use an outer join, selecting only those rows that don't match

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

This this running in SQL Fiddle

Note that using a join will out-perform a sub-query approach, especially when data sets become large.

于 2013-05-29T03:07:07.137 回答
5 
SELECT `ID`, `Name` FROM `TEAM` 
  WHERE `ID` NOT IN (SELECT DISTINCT(`Team_ID`) from `Games`) 
  AND `State` = 'TX';

SqlFiddle在这里。

于 2013-05-29T02:57:35.163 回答
4

You can also left-join to the Games table and filter for where there isn't a corresponding Games row. This is usually faster than NOT IN when the tables have a lot of rows:

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;

If there isn't a Games row to go with the Teams row, the Games.ID column will be null in the result, so if you filter on Games.ID IS NULL you'll get all the rows where a team has no games.

There's a SQL Fiddle here.

于 2013-05-29T03:09:48.727 回答
1

Hope this would help.

select t.ID,t.NAME
FROM Team t
WHERE t.state = 'TX'
AND t.id NOT IN (SELECT g.TEAM_ID FROM Games g)
于 2013-05-29T03:06:11.063 回答