Question

我试图通过SQLLite了解一下有关Android持久性的ORM工具，所以我决定编写一个小测试应用程序。但是，我似乎无法解决这个问题。我似乎完成了所有工作，例如OrmLite docs的Account，Orders示例。但是，我一直得到同样的错误：

外部集合类com.example.dataobjects.LocationObject用于字段＆＃39;位置＆＃39; column-name不包含com.example.dataobjects.TripObject类的外部字段

我试图在LocationObject和TripObject之间建立一对多的关系（一个TripObject有很多LocationObjects）

LocationObject：

@DatabaseTable
public class LocationObject {

private static final String TRIP_ID_FIELD_NAME = "trip_id";

@DatabaseField(generatedId = true)
private int Id;

@DatabaseField
private double latitude;

@DatabaseField
private double longitude;

@DatabaseField(foreign = true, foreignAutoRefresh = true, columnName = TRIP_ID_FIELD_NAME)
private TripObject trip;


public LocationObject()
{

}

public LocationObject(TripObject trip, double latitude, double longitude) {
    this.trip = trip;
    this.latitude = latitude;
    this.longitude = longitude;
}


@Override
public String toString() {
    return "LocationObject [Id=" + Id + ", latitude=" + latitude
            + ", longitude=" + longitude + "]";
}

}

TripObject：

@DatabaseTable
public class TripObject {

@DatabaseField(generatedId = true)
private int Id;

@DatabaseField
private String description;

@DatabaseField
private Date createdAt;

@DatabaseField
private int noOfPotholes;

@DatabaseField
private int noOfSpeedbumps;

@ForeignCollectionField
private ForeignCollection<LocationObject> locations;

public TripObject()
{

}

public TripObject(String description, Date createdAt, int noOfPotholes,
        int noOfSpeedbumps) {
    super();
    this.description = description;
    this.createdAt = createdAt;
    this.noOfPotholes = noOfPotholes;
    this.noOfSpeedbumps = noOfSpeedbumps;
    this.createdAt = new Date();
}

public ForeignCollection<LocationObject> getLocations()
{
    return this.locations;
}


@Override
public String toString() {
    return "TripObject [Id=" + Id + ", description=" + description
            + ", createdAt=" + createdAt + ", noOfPotholes=" +                   noOfPotholes
            + ", noOfSpeedbumps=" + noOfSpeedbumps + ", locations="
            + locations + "]";
}

}

我想要做的是测试一些插入和查询以了解该工具的工作原理，但我似乎陷入困境。

添加活动：

private DatabaseHelper dbHelper;

private void testAddRetrieve() throws SQLException
{
    dbHelper = OpenHelperManager.getHelper(this, DatabaseHelper.class);

    RuntimeExceptionDao<TripObject, Integer> tripDao = dbHelper.getTripRuntimeExceptionDao();
    RuntimeExceptionDao<LocationObject, Integer> locationDao = dbHelper.getLocationRuntimeExceptionDao();


    TripObject trip = new TripObject("Test Trip 1", new Date(), 12, 2);
    tripDao.create(trip);

    TripObject queriedTrip = tripDao.queryBuilder().where().eq("Id", 1).queryForFirst();


    Toast.makeText(this,"Trip added: " + queriedTrip.toString(), Toast.LENGTH_LONG).show();
    System.out.println("Trip added: " + queriedTrip.toString());


    // add
    locationDao.create(new LocationObject(trip, 25.5,32.4));
    locationDao.create(new LocationObject(trip, 23.5,41.4));
    locationDao.create(new LocationObject(trip, 12.5,34.4));

    // query
    List<LocationObject> locations = locationDao.queryForAll();

    Toast.makeText(this, "Locations retrieved: " + locations.toString(), Toast.LENGTH_LONG).show();
    System.out.println("Locations retrieved: " + locations.toString());

    OpenHelperManager.releaseHelper();
}

ORMLite：外部集合类不包含类异常的外部字段

0 个答案: