mysql - 在 MySQL 中创建外键

Question

我尝试使用 MySQL 工作台在 MySQL 中创建外键。但有一个错误

$ Executing:
ALTER TABLE `project_course`.`attendance` 
ADD CONSTRAINT `FK_Student`
  FOREIGN KEY ('idStudent')
  REFERENCES `project_course`.`student` ('userid')
  ON DELETE NO ACTION
  ON UPDATE NO ACTION;

Operation failed: There was an error while applying the SQL script to the database.
ERROR 1064: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ''idStudent')
  REFERENCES `project_course`.`student` ('userid')
  ON DELETE NO A' at line 3
SQL Statement:
ALTER TABLE `project_course`.`attendance` 
ADD CONSTRAINT `FK_Student`
  FOREIGN KEY ('idStudent')
  REFERENCES `project_course`.`student` ('userid')
  ON DELETE NO ACTION
  ON UPDATE NO ACTION

Answer 1

问题出在引号上(在 PC 上它位于 Enter 键周围)。您已使用它们代替反引号(在 PC 上，它位于 Esc 键下)。

ALTER TABLE `project_course`.`attendance` 
ADD CONSTRAINT `FK_Student`
  FOREIGN KEY (`idStudent`) # Change them here around `idStudent` 
  REFERENCES `project_course`.`student` (`userid`) # and here around `userid` 
  ON DELETE NO ACTION
  ON UPDATE NO ACTION;