Mongodb Grails GORM Mongo有许多未保存的关联

我有一个具有一对多关联的域类。看起来是这样的：

class FormResponse {

    static String DRAFT = 'Draft'
    static String SUBMITTED = 'Submitted'
    static String REJECTED = 'Rejected'
    static String APPROVED = 'Approved'

    static mapWith = "mongo"

    ObjectId id
    Date dateCreated
    Date lastUpdated
    User createdBy
    User updatedBy
    Form form
    String currentStatus = DRAFT
    List<FormSectionResponse> formSectionResponses
    List<FormResponseComment> formResponseComments

    static hasMany = [ formSectionResponses: FormSectionResponse, formResponseComments: FormResponseComment ]

    static mapping = {
    }

    static constraints = {
        updatedBy nullable: true
    }

}

def saveFormResponse(FormResponse formResponse) {
   def saved = formService.saveFormResponse(formResponse)
   respond(saved)
}

我有一个保存此对象的控制器方法，如下所示：

class FormResponse {

    static String DRAFT = 'Draft'
    static String SUBMITTED = 'Submitted'
    static String REJECTED = 'Rejected'
    static String APPROVED = 'Approved'

    static mapWith = "mongo"

    ObjectId id
    Date dateCreated
    Date lastUpdated
    User createdBy
    User updatedBy
    Form form
    String currentStatus = DRAFT
    List<FormSectionResponse> formSectionResponses
    List<FormResponseComment> formResponseComments

    static hasMany = [ formSectionResponses: FormSectionResponse, formResponseComments: FormResponseComment ]

    static mapping = {
    }

    static constraints = {
        updatedBy nullable: true
    }

}

def saveFormResponse(FormResponse formResponse) {
   def saved = formService.saveFormResponse(formResponse)
   respond(saved)
}

以及服务方法：

def saveFormResponse(response) {
    return response.save(flush: true, failOnError: true)
}

当我发布到该方法时，我可以看到formResponseComments列表按我预期的方式填充：

并保存FormResponseComment：

但是FormResponse对象未接收到与子FormResponseComment的关联：

class FormResponseComment {

    static mapWith = "mongo"

    ObjectId id
    Date dateCreated
    Date lastUpdated
    User createdBy
    String comment

    static belongsTo = [FormResponse]

    static mapping = {
    }

    static constraints = {
    }

}

那么，为什么协会不是在这里成立的呢

---

Grails 3.3.3.

通过向FormResponseComment域类添加反向引用进行修复，如下所示：

class FormResponse {

    static String DRAFT = 'Draft'
    static String SUBMITTED = 'Submitted'
    static String REJECTED = 'Rejected'
    static String APPROVED = 'Approved'

    static mapWith = "mongo"

    ObjectId id
    Date dateCreated
    Date lastUpdated
    User createdBy
    User updatedBy
    Form form
    String currentStatus = DRAFT
    List<FormSectionResponse> formSectionResponses
    List<FormResponseComment> formResponseComments

    static hasMany = [ formSectionResponses: FormSectionResponse, formResponseComments: FormResponseComment ]

    static mapping = {
    }

    static constraints = {
        updatedBy nullable: true
    }

}

def saveFormResponse(FormResponse formResponse) {
   def saved = formService.saveFormResponse(formResponse)
   respond(saved)
}

static belongsTo=[formResponse:formResponse]