使用ORMLite在Android问题节能系列 [英] Problems saving Collection using ORMLite on Android

问题描述

我有两个类：

public class Questionnaire {

    @DatabaseField(generatedId=true, useGetSet=true)
    private Long id;

    @DatabaseField
    private int type;

    @DatabaseField
    private String title;

    @DatabaseField
    private String description;


    @ForeignCollectionField(eager = true)   
    private Collection<Question> questions; 
// Get and Set omitted

和

  public class Question {

        @DatabaseField(generatedId=true, useGetSet=true)
        private Long id;

        @DatabaseField
        private int type;

        @DatabaseField
        private String description;


        @DatabaseField(foreign = true, foreignAutoRefresh= true)
        private Questionnaire questionario;
//get and set ommited

当我保存问题列表的问卷调查。这些对象持久化，但我输的关系。

When I save a Questionnaire with a List of Questions. The objects are persisted, but I lose the relationship.

我保存了这种方式：

ForeignCollection<Question> questions =
    getDao(Questionnaire.class).getEmptyForeignCollection("questions");

for(Question question : DataUtil.getAllQuestions()) {
    questions.add(question);
}

Questionnaire questionnarie = new Questionnaire();
questionnarie.setQuestions(questions);
questionnarie.setTitle("Normal");
questionnarie.setDescription("Questionário normal");
getDao(Questionnaire.class).createOrUpdate(questionarie);

当我从检索数据库这个寄存器，一个问题数据不具有问卷和参考我的问卷没有问题列表填充。

When I retrieved this register from database, a Question data doesn't have a reference for Questionnaire, and my Questionnaire doesn't have question list filled.

任何帮助将AP preciated。

Any help will be appreciated.

推荐答案

现在的问题是，你不设置你的问题上的 questionario 字段的对象。的关系是从问题的关联问卷。没有任何的问卷表指向的其他方式。请参阅文档外国对象。

The problem is that you are not setting the questionario field on your Question objects. The relationship is from the Question to the associated Questionnaire. There is nothing in the Questionnaire table that points the other way. See the documentation on foreign objects.

我会建议做一些这样的：

I would recommend doing something like the following:

Dao<Questionnaire, Long> dao = getDao(Questionnaire.class);
ForeignCollection<Question> questions =
    dao.getEmptyForeignCollection("questions");

Questionnaire questionnarie = new Questionnaire();
questionnarie.setQuestions(questions);
questionnarie.setTitle("Normal");
questionnarie.setDescription("Questionário normal");
dao.createOrUpdate(questionarie);

for(Question question : DataUtil.getAllQuestions()) {
    // you must set the questionnarie field on the Question
    // if it is a generated-id, it must be set _after_ it has been created
    question.setQuestionnaire(questionnarie);
    questions.add(question);
}

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