我正在尝试使用 MySQL 创建下表:
CREATE TABLE registrations (
eventNumber CHAR(3) UNIQUE NOT NULL
CHECK (EXISTS (SELECT eventNumber FROM events)),
employeeNumber CHAR(5) UNIQUE NOT NULL
CHECK (EXISTS (SELECT employeeNumber FROM employees)),
PRIMARY KEY(eventNumber , employeeNumber ),
FOREIGN KEY (eventNumber) REFERENCES eventNumber (employees)
ON UPDATE RESTRICT
ON DELETE RESTRICT,
FOREIGN KEY (employeeNumber ) REFERENCES employeeNumber(employees)
ON UPDATE RESTRICT
ON DELETE RESTRICT
) ENGINE=InnoDB;
但是,当我运行命令时出现无法创建表错误 (1005)。这里可能出了什么问题?