动态fnder findAllBy使用grails从连接表中获取多对多关系的空值

Question

我有3个域作为Subscriber，Role和一个连接表作为SubscriberRole，用于多对多的关系。动态查找器findAllBy从SubscriberRole域获取空值。

Subscriber.groovy ：

class Subscriber extends PartyRole{

    Date dateCreated
    Date lastUpdated
    List<Contact> contacts =  new ArrayList<Contact>();

    static belongsTo = [ customer: Customer]
    static hasMany = [seats: Seat, ownedEnquiries: Enquiry,enquiresSharedWith: SharedEnquiry, enquiriesSharedBy: SharedEnquiry ,
    managedTeams: Team , memberships: Membership, contacts: Contact , sharedByContacts: SharedContact, sharedWithContacts: SharedContact,
    vContacts: VContact, partOf: VContact,  sharedbyVContacts: SharedVcontact, sharedWithVcontacts: SharedVcontact, tokens : Token,
    notifications: Notification, discussions: Discussion]
    static mappedBy = [ managedTeams : "manager" , enquiresSharedWith: "sharedWith" , enquiriesSharedBy: "sharedBy"  ,
                                                   sharedByContacts : "sharedBy" , sharedWithContacts : "sharedWith" ,
                                                   vContacts: "forSubscriber"  ,  partOf :"ofContact",
                                                   sharedbyVContacts: "sharedby" , sharedWithVcontacts :"sharedWith"
                                                    ]

    StatusEnum status
    static constraints = {

        contacts nullable: true
        notifications nullable : true

    }


    Set<Role> getAuthorities() {
        SubscriberRole.findAllBySubscriber(this).collect { it.role } as Set
    }

    public Subscriber(){
        contacts = LazyList.decorate(contacts,  FactoryUtils.instantiateFactory(Contact.class))
    }




}

SubscriberRole.groovy：域

import org.apache.commons.lang.builder.HashCodeBuilder

class SubscriberRole implements Serializable {

    Subscriber subscriber
    Role role
    Date dateCreated
    Date lastUpdated

    boolean equals(other) {
        if (!(other instanceof SubscriberRole)) {
            return false
        }

        other.subscriber?.id == subscriber?.id &&
            other.role?.id == role?.id
    }

    int hashCode() {
        def builder = new HashCodeBuilder()
        if (subscriber) builder.append(subscriber.id)
        if (role) builder.append(role.id)
        builder.toHashCode()
    }

    static SubscriberRole get(long subscriberId, long roleId) {
        find 'from SubscriberRole where subscriber.id=:subscriberId and role.id=:roleId',
            [subscriberId: subscriberId, roleId: roleId]
    }

    static SubscriberRole create(Subscriber subscriber, Role role, boolean flush = false) {
        new SubscriberRole(subscriber: subscriber, role: role).save(flush: flush, insert: true)
    }

    static boolean remove(Subscriber subscriber, Role role, boolean flush = false) {
        SubscriberRole instance = SubscriberRole.findBySubscriberAndRole(subscriber, role)
        if (!instance) {
            return false
        }

        instance.delete(flush: flush)
        true
    }

    static void removeAll(Subscriber subscriber) {
        executeUpdate 'DELETE FROM SubscriberRole WHERE subscriber=:subscriber', [subscriber: subscriber]
    }

    static void removeAll(Role role) {
        executeUpdate 'DELETE FROM SubscriberRole WHERE role=:role', [role: role]
    }

    static mapping = {
        id composite: ['role', 'subscriber']
        version false
    }
}

Role.groovy域：

package com.vproc.member

import java.util.Date;

class Role {

    String authority
    Date dateCreated
    Date lastUpdated

    static mapping = {
        cache true
    }


    static constraints = {
        authority blank: false, unique: true
    }
}

正如您从图像中看到的那样，subscriber_role有3个条目但是当我尝试使用findAllBySubscriber时，它会给我null值。任何想法，为什么会这样？

问题：即可。当我使用**

从SubscriberRole表中获取数据时

Subscriber subscriber = Subscriber.get(params.id) 
def subscriberRole = SubscriberRole.findAllBySubscriber(subscriber)

虽然SubscriberRole表在db中有条目，但我得到NULL [com.vproc.member.SubscriberRole：null]。 上面的动态查找器有什么问题。

Answer 1

它以这种格式显示你（[com.vproc.member.SubscriberRole：null]）。 null必须是因为您在SubscriberRole上有复合键。

但是你需要根据需要获得适当的数据。

对于表示，您可以将好的toString添加到SubscriberRole，例如

public String toString()
{
    return "${subscriber} :: ${role}"
}