mysql - 在 MySQL 中的两个表之间定义外键时遇到问题

Question

Error Code: 1215. Cannot add foreign key constraint

我不确定我在哪里遇到这个问题，这是有问题的两个表格，任何帮助将不胜感激!

CREATE TABLE IF NOT EXISTS `PHL_db`.`Session` (
  `year` INT NOT NULL,
  `season` VARCHAR(50) NOT NULL,
  `division` VARCHAR(25) NOT NULL,
  PRIMARY KEY (`year`, `season`, `division`))
ENGINE = InnoDB;

CREATE TABLE IF NOT EXISTS `PHL_db`.`Team` (
  `name` VARCHAR(100) NOT NULL DEFAULT 'Free Agent',
  `Session_season` VARCHAR(50) NOT NULL,
  `Session_year` INT NOT NULL,
  `Session_division` VARCHAR(25) NOT NULL,
  PRIMARY KEY (`name`, `Session_season`, `Session_year`, `Session_division`),
    FOREIGN KEY (`Session_season` , `Session_year` , `Session_division`)
    REFERENCES `PHL_db`.`Session` ( `year`, `season` , `division`)
    ON DELETE NO ACTION
    ON UPDATE NO ACTION)
ENGINE = InnoDB;

Answer 1

您正在尝试将主键设为外键，其中主键不能用作同一表上的外键。