我对 SQL 和 JPQL 的理解不是很好,我一直在尝试创建以下 sql 语句的 JPQL 查询:
select group.* from user, user_group, group
where user_group.user_id = user.id
and user_group.group_id = group.id
and user.id = [userID to search]
编辑:糟糕,我忘记将按用户 ID 搜索的部分添加到查询中。我想获取用户所属的所有组。
但我只是无法正确地获取语法。任何帮助将不胜感激。
相关代码片段:
组.java
@Table(name = "group")
@Entity
public class Group implements Serializable {
@Id
@GeneratedValue
@Column(name = "id")
private Integer id;
@JoinTable(name = "user_group", joinColumns = {
@JoinColumn(name = "group_id", referencedColumnName = "id")}, inverseJoinColumns = {
@JoinColumn(name = "user_id", referencedColumnName = "id")})
@ManyToMany
private Collection<User> userCollection;
}
用户.java
@Table(name = "user")
@Entity
public class User implements Serializable {
@Id
@NotNull
@GeneratedValue
@Column(name = "id")
private Integer id;
@Column(name = "email", unique=true, nullable=false)
private String email;
@ManyToMany(mappedBy = "userCollection")
private Collection<Group> GroupCollection;
}