我需要一份只有一名成员的团队列表。
sql:
CREATE TABLE `formsfiles`.`Teams` (
`ID` INT NOT NULL AUTO_INCREMENT ,
`Name` VARCHAR(45) NULL ,
PRIMARY KEY (`ID`) );
INSERT INTO `Teams` (`Name`) VALUES ('Sharks');
INSERT INTO `Teams` (`Name`) VALUES ('Jets');
INSERT INTO `Teams` (`Name`) VALUES ('Fish');
INSERT INTO `Teams` (`Name`) VALUES ('Dodgers');
INSERT INTO `Teams` (`Name`) VALUES ('Pigs');
CREATE TABLE `Players` (
`ID` INT NOT NULL AUTO_INCREMENT ,
`Name` VARCHAR(45) NULL ,
`Team_ID` INT NULL ,
PRIMARY KEY (`ID`) );
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Jim', '1');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Tom', '1');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Harry', '2');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Dave', '2');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Tim', '3');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Trey', '4');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Jay', '4');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Steve', '4');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Ziggy', '5');
INSERT INTO `Players` (`Name`, `Team_ID`) VALUES ('Chris', '4');
我应该得到答案
ID Name
3 Fish
5 Pigs
(这与之前提出的问题相反:请不要打败我!)
最佳答案
SELECT t.ID, t.Name
FROM Teams t
JOIN Players p ON t.ID=p.Team_ID
GROUP BY t.ID
HAVING COUNT(DISTINCT p.ID) = 1;
关于mysql - 获取只有一条相关记录的记录列表,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/16801040/