java - JPA加入多列

我有实体User，Organization和GrantedRole。它们的关系是，GrantedRole定义了用户在组织中的角色。这三个实体都从其超类继承字段“id”(用@Id注释)。组织没有对GrantedRole或User的引用，这些关系是单向的。

@Entity
@Table(name = "role_assignments", uniqueConstraints = @UniqueConstraint(columnNames = {
    "user_id", "organization_id" }))
public class GrantedRole extends DomainEntity implements GrantedAuthority {

    public static enum Role {
        ROLE_MODM_USER, ROLE_MODM_ORGADMIN, ROLE_MODM_ADMIN
    }

    private User user;
    private Role role;
    private Organization organization;

    public static enum Role {
        ROLE_MODM_USER, ROLE_MODM_ORGADMIN, ROLE_MODM_ADMIN
    }

    @ManyToOne
    @NotNull
    public User getUser() {
        return user;
    }

    @NotNull
    @Enumerated(EnumType.STRING)
    public Role getRole() {
        return role;
    }

    @ManyToOne
    public Organization getOrganization() {
        return organization;
    }

    // Some setters
}

@Entity
@Table(name = "modmUsers")
public class User extends DomainEntity implements UserDetails {
    // Some other fields

    private Set<GrantedRole> roles = new HashSet<GrantedRole>();
    private Set<Organization> organizations = new HashSet<Organization>();

    @OneToMany(fetch = FetchType.EAGER, mappedBy = "user")
    public Set<GrantedRole> getRoles() {
        return roles;
    }

    @ManyToMany(fetch = FetchType.EAGER)
    public Set<Organization> getOrganizations() {
        return organizations;
    }

    // Some setters
}

现在，我想使用JPA标准来查找用户具有ROLE_MODM_ORGADMIN角色的组织。但是，生成的查询将连接在单个列上，并导致重复GrantedRole中的行，因为User.id在GrantedRole中不是唯一的，而Organization.id也不是唯一的。两者的结合是独特的。

我找到组织的代码:

public List<Organization> findOrganizationsByOrgAdminUser(String
    CriteriaBuilder cb = entityManager.
    CriteriaQuery<Organization> query = cb.createQuery(Organization.
    Root<User> root = query.from(User.class);
    SetJoin<User, Organization> joinOrg = root.joinSet("organizations");
    SetJoin<User, GrantedRole> joinRoles = root.joinSet("roles");

    Predicate p1 = cb.equal(root.get("id"), userId);
    Predicate p2 = cb.equal(joinRoles.get("role"), Role.ROLE_MODM_ORGADMIN);

    query.select(joinOrg);
    query.where(cb.and(p1, p2));

    return entityManager.createQuery(query).getResultList();
}

生成的查询是:

SELECT
    orgs.*
FROM
    modmUsers users
INNER JOIN
    modmUsers_organizations u_o
        ON users.id=u_o.modmUsers_id
INNER JOIN
    organizations orgs
        ON u_o.organization_id=orgs.id
INNER JOIN
    role_assignments roles
        ON users.id=roles.user_id
WHERE
    users.id=?
    and roles.role=?

我想要的查询是:

SELECT
    orgs.*
FROM
    modmUsers users
INNER JOIN
    modmUsers_organizations u_o
        ON users.id=u_o.modmUsers_id
INNER JOIN
    organizations orgs
        ON u_o.organization_id=orgs.id
INNER JOIN
    role_assignments roles
        ON users.id=roles.user_id
        AND orgs.id=roles.organization_id //how to do this???
WHERE
    users.id=?
    and roles.role=?

最佳答案

好的，所以我的同事帮助了我，并导致我执行以下查询:

SELECT
    orgs.*
FROM
    modmUsers users
INNER JOIN
    modmUsers_organizations u_o
        ON users.id=u_o.modmUsers_id
INNER JOIN
    organizations orgs
        ON u_o.organization_id=orgs.id
INNER JOIN
    role_assignments roles
        ON users.id=roles.user_id
WHERE
    users.id=?
    AND roles.role=?
    AND orgs.id=roles.organization_id

这是我的代码的简单扩展:

public List<Organization> findOrganizationsByOrgAdminUser(String
    CriteriaBuilder cb = entityManager.
    CriteriaQuery<Organization> query = cb.createQuery(Organization.
    Root<User> root = query.from(User.class);
    SetJoin<User, Organization> joinOrg = root.joinSet("organizations");
    SetJoin<User, GrantedRole> joinRoles = root.joinSet("roles");

    Predicate p1 = cb.equal(root.get("id"), userId);
    Predicate p2 = cb.equal(joinRoles.get("role"), Role.ROLE_MODM_ORGADMIN);
    Predicate p3 = cb.equal(joinOrg.get("id"), joinRoles.get("organization"));

    query.select(joinOrg);
    query.where(cb.and(p1, p2, p3));

    return entityManager.createQuery(query).getResultList();
}