如何编写HQL来查询多对多?

时间:2012-10-15 12:43:03

标签: java hibernate hql

我有用户模型,系统允许用户互相关注。 所以我在User模型中放了两个列表,如下所示:

@ManyToMany(fetch = FetchType.LAZY)
@JoinTable(name = "t_user_t_followingUser", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = { @JoinColumn(name = "followingUser_id") })
public List<User> getFollowingUsers() {
    return followingUsers;
}

public void setFollowingUsers(List<User> followingUsers) {
    this.followingUsers = followingUsers;
}

@ManyToMany(fetch = FetchType.LAZY)
@JoinTable(name = "t_user_t_followedUser", joinColumns = { @JoinColumn(name = "user_id") }, inverseJoinColumns = { @JoinColumn(name = "followedUser_id") })
public List<User> getFollowedUsers() {
    return followedUsers;
}

public void setFollowedUsers(List<User> followedUsers) {
    this.followedUsers = followedUsers;
}

现在我想得到用户的总追随者。 如何编写HQL?

ps:很多人可能不合适。对设计有什么建议吗?

提前致谢。

1 个答案:

答案 0 :(得分:0)

试试这个SELECT COUNT(fu) FROM User AS u INNER JOIN u.followedUsers AS fu;