春季數據中的本機查詢聯接

Question

我有課：

@Entity
public class User {
    @Id
    Long id;
    String name;

    @ManyToMany
    List<Mission> missions;
}

@Entity
public class Mission {
    @Id
    Long id;
    String name;

    @ManyToMany
    List<User> users;
}

public interface MissionRepository extends CrudRepository<Mission, Long> {
    @Query(nativeQuery = true, "select * from mission join user on id = user_id where name = ?1")
    public List<Mission> findByname(String name);
}

我想知道是否可以在 Spring Data JPA 中使用本機查詢連接，以及查詢結果是否正確映射到上述示例中的實體。

有人可以給我看一個完整的例子來使用它。 在我的情況下，我必須使用本機查詢，但我不確定它是否有效。

Answer 1

您可以通過使用命名的本機查詢和結果集映射來做到這一點，這是一個完整的例子

任務實體

package com.ntg.crm.internal.entites;

import java.math.BigInteger;
import java.util.List;

import javax.persistence.Entity;
import javax.persistence.EntityResult;
import javax.persistence.FetchType;
import javax.persistence.FieldResult;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.NamedNativeQuery;
import javax.persistence.SqlResultSetMapping;

@SqlResultSetMapping(name = "Mission.findAllMissionsMapping", entities = @EntityResult(entityClass = Mission.class, fields = {
        @FieldResult(name = "name", column = "mname"), @FieldResult(name = "id", column = "mid")
}))
@NamedNativeQuery(name = "Mission.findAllMissions", query = "select m.id as mid,m.name as mname , info.id uid ,info.name uname from Mission m join user_info_missions um on m.id "
        + "= um.missions_id join user_Info info on info.id = um.user_id where info.name =:userName", resultSetMapping = "Mission.findAllMissionsMapping")

@Entity
public class Mission {

    public Mission() {

    }

    public Mission(BigInteger id, String name) {
        super();
        this.id = id;
        this.name = name;
    }

    public Mission(BigInteger id, String name, List<User> users) {
        super();
        this.id = id;
        this.name = name;
        this.users = users;
    }

    @Id
    BigInteger id;
    String name;

    @ManyToMany(fetch = FetchType.EAGER)
    @JoinTable(name = "user_info_missions", joinColumns = @JoinColumn(name = "missions_id"), inverseJoinColumns = @JoinColumn(name = "user_id"))
    List<User> users;

    public BigInteger getId() {
        return id;
    }

    public void setId(BigInteger id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<User> getUsers() {
        return users;
    }

    public void setUsers(List<User> users) {
        this.users = users;
    }

}

用戶實體

package com.ntg.crm.internal.entites;

import java.util.List;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.Table;

import com.fasterxml.jackson.annotation.JsonIgnore;

@Entity
@Table(name = "userInfo")
public class User {

    @Id
    long id;
    String name;

    @ManyToMany(targetEntity = Mission.class)
    @JoinTable(name = "user_info_missions", joinColumns = @JoinColumn(name = "user_id"), inverseJoinColumns = @JoinColumn(name = "missions_id"))
    @JsonIgnore
    List<Mission> missions;

    public long getId() {
        return id;
    }

    public void setId(long id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public List<Mission> getMissions() {
        return missions;
    }

    public void setMissions(List<Mission> missions) {
        this.missions = missions;
    }

}

存儲庫功能

public List<Mission> findAllMissions(@Param("userName") String userName);

控制器功能

@Autowired
    TestRepository testRepo;

    @RequestMapping(value = "", method = RequestMethod.GET, produces = "application/json", consumes = "application/json")
    @ResponseBody
    List<Mission> getall() {
        List<Mission> missions = testRepo.findAllMissions("Test");
        return missions;
    }

這就是結果

[
  {
    "id": 1,
    "name": "Mission 1",
    "users": [
      {
        "id": 1,
        "name": "Test"
      }
    ]
  },
  {
    "id": 2,
    "name": "Mission 2",
    "users": [
      {
        "id": 1,
        "name": "Test"
      }
    ]
  }
]

Answer 2

@middy62 您可以使用下面的查詢。 我已經使用您的示例來編寫查詢。 希望它可以幫助某人。

---

@Query(nativeQuery = true, value = "select m from Mission join m.user u where name =:name") public List<Mission> findByname(@Param("name") String name);

請注意，當您在域實體模型上正確映射時，查詢有效。

Answer 3

您可以使用 Native Spring Data JPA 並使用連接。 這將返回對象數組

public interface MissionRepository extends Repository<Mission, Long> {

@Query(value = "SELECT * from mission m 
                inner join user u 
                on m.id = u.id 
                where m.name=:name", nativeQuery = true)
List<Object[]> findByname(@Param("name") string name);
}