[英]Additional column in the intermediate table in many to many replationship in jpa
我有兩個類Game和Team,它們之間有多對多的關系。
游戲:
@Entity
@Table(name = "GAME")
public class Game extends Model {
@ManyToMany(cascade = {CascadeType.ALL})
@JoinTable(name="GAME_TEAM",
joinColumns={@JoinColumn(name="GAME_ID")},
inverseJoinColumns={@JoinColumn(name="TEAM_ID")})
private List<Team> teams = new ArrayList<Team>();
public List<Team> getTeams() {
return teams;
}
public void setTeams(List<Team> teams) {
this.teams = teams;
}
}
球隊:
@Entity
@Table(name = "TEAM")
public class Team extends Model {
@Column(name = "TEAM_NAME")
private String teamName;
@OneToMany(mappedBy = "team", fetch = FetchType.EAGER, cascade = CascadeType.ALL, orphanRemoval = true)
private Set<Player> player = new LinkedHashSet<Player>();
@ManyToMany(cascade=CascadeType.ALL, mappedBy="teams")
private Set<Game> games;
public Set<Player> getPlayer() {
return player;
}
public void setPlayer(Set<Player> player) {
this.player = player;
}
public Set<Game> getGames()
{
return games;
}
public void setGames(Set<Game> games) {
this.games = games;
}
public String getTeamName() {
return teamName;
}
public void setTeamName(String teamName) {
this.teamName = teamName;
}
在這兩個類GAME_TEAM之間有第三個中間表,它具有team_id,game_id是游戲和團隊類的ID的外鍵。 因此,每當我更新團隊和游戲時,我都會自動更新game_team。
好。 好。 現在問題是什么? 我有第三列WON_BY,也需要更新。 如果沒有這個額外的第三列,我就不必創建第三類GameTeam。
要更新不是外鍵的第三列,我應該為中間表創建實體類嗎? 如果是這樣,我應該使用什么樣的方法或注釋?
你需要有一個單獨的實體類來保持你的'WON_BY',你需要稍微重新考慮你現有的實體類,因為解決方案很大,請參考下面的示例示例,這肯定會解決您的問題。
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