java - Hibernate/Spring Data 上的级联删除

Question

我有以下实体:

@Entity
public class Car { ... }

@Entity
public class Driver {
    @ManyToOne(cascade=CascadeType.ALL)
    @JoinColumn(name = "CAR_ID")
    private Car car;

    ...
}

@Entity
public class Penalty {
    @ManyToOne(cascade=CascadeType.ALL)
    @JoinColumn(name="D_ID")
    private Driver driver;

    ...
}

我希望在将 Car 删除为 carRepository.delete(car_id)< 时删除来自 Driver 和 Penalty 的所有信息.

WARN : org.hibernate.engine.jdbc.spi.SqlExceptionHelper - SQL Error: 1451, SQLState: 23000
ERROR: org.hibernate.engine.jdbc.spi.SqlExceptionHelper - Cannot delete or update a parent row: a foreign key constraint fails (`test`.`car_drivers`, CONSTRAINT `FK9ux9oqx6yr66cva4ro6l8m63r` FOREIGN KEY (`CAR_ID`) REFERENCES `cars` (`CAR_ID`))
ERROR: org.hibernate.internal.ExceptionMapperStandardImpl - HHH000346: Error during managed flush [org.hibernate.exception.ConstraintViolationException: could not execute statement]
ERROR: com.app.cars.controller.AdminController - Exception during deleting car due to  could not execute statement; SQL [n/a]; constraint [null]; nested exception is org.hibernate.exception.ConstraintViolationException: could not execute statement

无法更改表属性和设计。因此，需要通过修复实体模型来消除此错误。

Answer 1

您的实体模型不会将删除级联到Driver，然后级联到Penalty，因此数据库会引发约束违规错误。模型应如下所示:

@Entity
class Car {
  @OneToMany(cascade = CascadeType.ALL, mappedBy = "car", orphanRemoval = true)
  private Set<Driver> drivers;

  ...
}

@Entity
class Driver {
  @ManyToOne
  private Car car;

  @OneToMany(cascade = CascadeType.ALL, mappedBy = "driver", orphanRemoval = true)
  private Set<Penalty> penalties;

  ...
}

@Entity
class Penalty {
  @ManyToOne
  private Driver driver;

  ...
}