休眠和查询视图。 结果计数正常，但所有行都相同但不在数据库中

Question

I have an entity representing a view on the (mysql) database:

@Entity
@Immutable
@Table(name = "user_info_view")
public class UserInfoView implements Serializable {

    @Id
    @Column(name = "user_uuid")
    private String userUUID;

    @Column(name = "name")
    private String name;

    @Column(name = "address")
    private String address;

    //getters, setters, constructors...

    }

The view is created using a simple SQL, like:

CREATE OR REPLACE VIEW USER_INFO_VIEW
AS
    SELECT u.USER_UUID,
           u.NAME,
           a.ADDRESS
    FROM
    USER u
    JOIN
    ADDRESS a
    ON a.ID = u.ADDRESS_ID

And a repository:

@Repository
public interface UserInfoViewRepository extends JpaRepository<UserInfoView, String> {

    List<UserInfoView> findAllByUserUUID(String userUUID);
    
}

SELECT * FROM USER_INFO_VIEW is returning 4 rows. Running findAllByUserUUID() method returns a list of 4 UserInfoView objects, but they are all the same - and they contain data from the first row in the database.

Here are the results of queries on the database:

SELECT * FROM USER:

id | user_uuid | name | address_id |
------------------------------------
1  | UUID1     | john | 1          |
2  | UUID1     | jane | 2          |
3  | UUID1     | josh | 3          |
4  | UUID1     | mark | 4          |
------------------------------------ 

SELECT * FROM ADDRESS:

id | address            | name  | is_current |
----------------------------------------------
1  | some address 1     | addr1 | 1          |
2  | some address 2     | addr2 | 0          |
3  | some address 3     | addr3 | 1          |
4  | some address 4     | addr4 | 1          |
---------------------------------------------- 

SELECT * FROM USER_VIEW WHERE USER_UUID = "UUID1":

user_uuid | name | address            |
---------------------------------------
UUID1     | john | some address 1     |
UUID1     | jane | some address 2     |
UUID1     | josh | some address 3     |
UUID1     | mark | some address 4     |
---------------------------------------

What could be causing this behaviour?

Answer 1

The fact that the user_uuid column is not unique causes the duplicates since it's marked as @Id and JPA uses its value to find the entities. You'll need a composite PK using either an IdClass or an EmbeddedId containing the identifiying attributes.