Question

我的实体如下

@Entity
@Table(
    name = "t1",
    uniqueConstraints = {
            @UniqueConstraint(name = "u1", columnNames = {"u1"}),
            @UniqueConstraint(name = "u2", columnNames = {"u2_id"}) //This does not enforce uniqueness
    }
)
public class t1
{

    @Id
    @GeneratedValue
    private Long id;

    @Column(nullable = false)
    private String u1; //Uniqueness is enforced here

    @OneToOne
    @JoinColumn(unique = true) //This does not enforce uniqueness
    private U2 u2;

}

@Entity
@Table(
    name = "u2",
    uniqueConstraints = {
            @UniqueConstraint(name = "p1", columnNames = {"p1"})
    }
)
public class u2
{

    @Id
    @GeneratedValue
    private Long id;

    @Column(nullable = false)
    private String p1; //Uniqueness is enforced here

}

通过

创建和更新实体

t1 t1_0 = new t1("t1_0");
t1 t1_1 = new t1("t1_1");
u2 u2_0 = new u2("u2_0");

repository.save(t1_0);
repository.save(t1_1);
repository.save(u2_0);

t1_0 = repository.findOne(t1_0.getId());
t1_1 = repository.findOne(t1_1.getId());

t1_0.setu2(u2_0);
t1_1.setu2(u2_0);

事务结束后，t1_0.u2与u2_0相连，t1_1.u2与u2_0相关联。我预计它会抛出唯一性约束违例异常。

不明白出了什么问题。 SO上的其他主题建议@JoinColumn(unique = true)应该这样做。

修改这包含在一个事务中

t1_0 = repository.findOne(t1_0.getId());
t1_1 = repository.findOne(t1_1.getId());

t1_0.setu2(u2_0);
t1_1.setu2(u2_0);

EDIT2

由于某些原因，我也无法访问数据库。控制台视图加载但在添加密码后显示用户空白页面（某些网络查询失败）。

但我可以从日志中看到创建外键和唯一约束

Hibernate: alter table driver add constraint UK_ssh305wwvomjtn6opolug33nj unique (cardo_id)

Hibernate: alter table car add constraint FKosnia01vhqwmm888uxrg4o6f6 foreign key (manufacturerdo_id) references manufacturer

Hibernate: alter table driver add constraint FK3yb5ci9sr6ieo6n4wwwef3puv foreign key (cardo_id) references car

添加时

Answer 1

我的交易无效。由于他们没有看到对方的数据，我错误地在另一个内创建了一个。

Answer 2

应使用逗号引入列名称（如果多于一个）。你的惯例是错误的

免责声明：未在真实数据库中检查

@Table(
    name = "t1",
    uniqueConstraints = {
            @UniqueConstraint(name = "u1", columnNames = {"u1"}),
            @UniqueConstraint(name = "u2", columnNames = {"u2", "id"}) // comma    
                        }

)

Spring JPA @JoinColumn（unique = true）不起作用

2 个答案: