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这是一个RBAC模块,有三个基本的表用户,角色和权限以及中间映射表user_role和role_permission。使用Criteria API和Metamodel API连接两个中间表总是交叉连接
@Entity
@Table(name = "USER")
public class User implements Serializable {
@Id
private String userId;
...
}
@Entity
@Table(name = "ROLE")
public class Role implements Serializable {
@Id
private String roleId;
...
}
@Entity
@Table(name = "PERMISSION")
public class Permission implements Serializable {
@Id
private String permissionId;
...
}
@Entity
@Table(name = "USER_ROLE")
public class UserRole implements Serializable {
@Id
@GenericGenerator(name = "uuidGenerator", strategy = "uuid")
@GeneratedValue(generator = "uuidGenerator")
@Column(name = "ID")
private String id;
@ManyToOne
@JoinColumn(name = "USERID")
private User user;
@ManyToOne
@JoinColumn(name = "ROLEID")
private Role role;
...
}
@Entity
@Table(name = "ROLE_PERMISSION")
public class RolePermission implements Serializable {
@Id
private String id;
@ManyToOne
@JoinColumn(name = "PERMISSIONID")
private Permission permission;
@ManyToOne
@JoinColumn(name = "ROLEID")
private Role role;
...
}
,现在我想找到user.id所有权限,SQL表达这样的:
select rp.* from Role_Permission rp,User_Role ur where ur.roleId = rp.roleId and ur.userId = :id
而是通过标准API:
public Predicate toPredicate(Root<RolePermission> root, CriteriaQuery<?> criteriaQuery, CriteriaBuilder criteriaBuilder) {
List<Predicate> predicates = new ArrayList<Predicate>();
if (StringUtil.isNotEmpty(userId)) {
final Root<UserRole> userRoleRoot = criteriaQuery.from(UserRole.class);
Join<RolePermission,UserRole> join = root.join("role", JoinType.INNER);
Predicate predicate = criteriaBuilder.equal(join.get("roleId"), root.get("role").get("roleId"));
predicate = criteriaBuilder.and(predicate,criteriaBuilder.equal(userRoleRoot.<UserRole>get("user").get("id"), userId));
predicates.add(predicate);
}
return criteriaBuilder.and(predicates.toArray(new Predicate[]{}));
}
和查询生成的结果是:
select count(rolepermis0_.id) as col_0_0_ from role_permission rolepermis0_ inner join role role2_ on rolepermis0_.roleid=role2_.roleid cross join user_role userrole1_ where role2_.roleid=rolepermis0_.roleid and userrole1_.userid=?
但为什么在这里role_permission交叉连接user_role,role_permission如何通过条件API加入user_role?
非常感谢。
首先您的JPQL无效。你在关系上做一个JOIN,而不是在一个班上。因此,从“从RolePermission rp inner join rp.role r中选择rp”开始。使用它来决定使用什么标准 –
JPQL只是一个假的代码。我真的只需要找到是RolePermission,像这样的SQL表达式:select rp。* from RolePermission rp,UserRole ur where ur.roleId = rp.roleId and ur。 userId =:id –
首先,如果它是“伪代码”,那么不要发布它。其次,如果你想添加一个谓词(“criteriaBuilder.equal”),你应该使用“join”而不是“root.get()。get()”。另外,如果你只有RolePermission中的关系,那么这就需要你成为Criteria中的“候选人”......是吗? –