Question

我有两个类Game和Team，它们之间有多对多的关系。

游戏：

@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;
}
}

小组：

@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;
}

在这两个类GAME_TEAM之间有第三个中间表，它有team_id，game_id是来自游戏和团队类的ID的外键。因此，每当我更新团队和游戏时，我都会自动更新game_team。

确定。好。现在问题是什么？我有第三列WON_BY，也需要更新。如果没有这个额外的第三列，我就不必创建第三类GameTeam。

要更新非外键的第三列，是否应该为中间表创建实体类？如果是这样，我应该使用什么样的方法或注释？

Answer 1

你需要一个单独的实体类来保持你的'WON_BY'，和你需要重新考虑现有的实体类，因为解决方案相当大，请参考下面的示例示例绝对能解决你的问题。

http://www.codejava.net/frameworks/hibernate/hibernate-many-to-many-association-with-extra-columns-in-join-table-example

中间表中的附加列，在jpa中有很多次重复

1 个答案: