CODEWITHSUNDEEP
javadatabaseentitiesjpa-2.1
Adnan Irshad
Adnan Irshad

Reputation: 3

getting error during the creation of relationship between JPA entities

I'm trying to create entities but I got the following error.

Internal Exception: Exception [EclipseLink-7157] (Eclipse Persistence Services - 2.5.2.v20140319-9ad6abd): org.eclipse.persistence.exceptions.ValidationException
Exception Description: Entity class [class application.Team] must use a @JoinColumn instead of @Column to map its relationship attribute [mPlayers].

These are my entities, I need to store data into the database using the Java Persistence API (JPA). To do so I create entities as following. Maybe I have created the relationships between entities in the wrong way.

Person

@MappedSuperclass
public class Person {
 @Id
 @GeneratedValue( strategy= GenerationType.AUTO )
 protected int p_id;

 protected String firstName;
 protected String middleName;
 protected String lastName;
 protected String phone; 
 protected String email;

 public Person() {
 }
}

Player

    @Entity
@Table( name = "tbl_players")
@AttributeOverride(name="id", column=@Column(name="player_id"))
public class Player extends Person implements Serializable{
    private int player_id;

    @Column(name = "goals_in_year")
    private int numberOfGoalsInCurrentYear;

    private boolean goalie;

    @Column(name = "defended_goals")
    private int defendedGoals;

    public Player(){

    }
 }

Manager

@Entity
@Table( name = "tbl_manager")
@AttributeOverride(name="id", column=@Column(name="manager_id"))
public class Manager extends Person implements Serializable{
    private String dob;
    private int starRating;

    @OneToOne
    private Team teamToManage;

    public Manager(){
    }
}

Team

@Entity
@Table( name = "tbl_team")
public class Team implements Serializable {
    @Column(name = "team_name")
    @Id
    String teamName;

    @OneToOne
    Manager manager;

    @Column(name = "team_players")
    @OneToMany
    private List<Player> mPlayers = new ArrayList<>();

    @Column(name = "jersey_color")
    String jerseyColor;

    public Team(){
    }
}

League

@Entity
public class League {
    @Id
    private int league_id;

    @OneToMany
    @Column(name = "League Teams")
    private List<Team> mTeam = new ArrayList<>();

    public void addTeam(Team team) {
        mTeam.add(team);
    }

    public void removeTeam(Team team) {
        mTeam.remove(team);
    }
}

Upvotes: 0

Views: 137

Answers (4)

ThilankaD
ThilankaD

Reputation: 1099

Player

@Entity
@Table( name = "tbl_players")
@AttributeOverride(name="id", column=@Column(name="player_id"))
public class Player extends Person implements Serializable{
    private int player_id;

    @Column(name = "goals_in_year")
    private int numberOfGoalsInCurrentYear;

    private boolean goalie;

    @Column(name = "defended_goals")
    private int defendedGoals;

    @OneToOne // or @OneToMany as you desire
    @JoinColumn(name="team_name") // here the name you have given to the column in tbl_players
    private Team team;

    public Player(){

    }
 }

Manager

@Entity
@Table( name = "tbl_manager")
@AttributeOverride(name="id", column=@Column(name="manager_id"))
public class Manager extends Person implements Serializable{
    private String dob;
    private int starRating;

    @OneToOne(mappedBy="manager")
    private Team teamToManage;

    public Manager(){
    }
}

Team

@Entity
@Table( name = "tbl_team")
public class Team implements Serializable {

    @Id
    @Column(name = "team_id")
    private int id;    

    @Column(name = "team_name")
    String teamName;

    @OneToOne
    @JoinColumn(name="manager_id")
    Manager manager;

    @Column(name = "team_players")
    @OneToMany(mappedBy="team")
    private List<Player> mPlayers = new ArrayList<>();

    @Column(name = "jersey_color")
    String jerseyColor;

    @ManyToOne(mappedBy="")
    private League league;

    public Team(){
    }
}

League

@Entity
@Table( name = "tbl_league")
public class League {

    @Id
    @Column(name="league_id")
    private int league_id;

    @OneToMany
    @JoinTable(name="tbl_league_teams",joinColumns=@JoinColumn(name = "league_id"), inverseJoinColumns=@JoinColumn(name = "team_id"))
    private List<Team> mTeam = new ArrayList<>();

    public void addTeam(Team team) {
        mTeam.add(team);
    }

    public void removeTeam(Team team) {
        mTeam.remove(team);
    }
}

Create new intermiditate mapping table named tbl_league_teams with columns league_id and team_id to facilitate the @JoinTable in League entity to map between teams in a league.

Upvotes: 0

Morgan Denis
Morgan Denis

Reputation: 111

Why dont u treat each model class as an entity then u join the model using either ManyToOne or OneToMany

Upvotes: 0

Joy
Joy

Reputation: 424

Use @JoinColumn for Mapping (@OneToMany, @ManyToMany, @ManyToOne) instead of @Column. @Column is used to specify the mapped column for a persistent property or field.

Upvotes: 1

Sam
Sam

Reputation: 153

It seems to be due to @Column(name = "team_players") and @OneToManyPlease

Please read the link https://stackoverflow.com/a/24206471/11207493

Upvotes: 0

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