java - @ManyToMany 关系不保存

Question

我有一些具有@ManyToMany 关系的实体:

@ManyToMany(cascade = CascadeType.ALL, fetch = FetchType.EAGER)
@JoinTable(name = "buses_drivers",
        joinColumns = @JoinColumn (name = "driver_id_inner", referencedColumnName = "driver_id"),
        inverseJoinColumns = @JoinColumn (name = "bus_id_inner", referencedColumnName = "bus_id"))
private List<Bus> buses;

和

@ManyToMany(mappedBy = "buses", fetch = FetchType.EAGER, cascade = CascadeType.ALL)
private List<Driver> drivers;

当用一些Bus模型执行保存Driver模型时，一切正常。表 buses_drivers 存储那些实体的所有键。但是当用驱动程序保存 Bus 模型时，表不会改变。我认为 inverseJoinColmns 映射有问题。

Answer 1

这是预期的行为。在双向多对多关联中，一侧必须是另一侧。在您的情况下，它是 Bus 端，因为它包含 mappedBy :

The field that owns the relationship. Required unless the relationship is unidirectional.

这意味着 Driver 是关联的所有者，Hibernate 只会在维护关联时检查这一方。