Question

我有一个BeaconBase类，其中包含BeaconData列表。

public class BeaconBase extends RealmObject {

    @PrimaryKey
    private Integer checkInID;

    @SerializedName("beacons")
    @Expose
    private RealmList<BeaconData> beacons;
}

public class BeaconData extends RealmObject {

    @SerializedName("scanId")
    @Expose
    private String scanId;

    @SerializedName("distance")
    @Expose
    private String distance;

}

BeaconData通常会很大。每小时可能大约有100000行。删除相关的BeaconBase记录时如何有效删除BeaconData？

我仅在BeaconBase中具有主键。

因此，当我删除BeaconBase记录时，成千上万个BeaconData记录被孤立了。我如何有效处理这种情况？

Answer 1

try(Realm r = Realm.getDefaultInstance)) {
    r.executeTransaction((realm) -> {
        RealmResults<BeaconBase> beaconsToDelete = realm.where(BeaconBase.class)./*query here*/.findAll();
        for(int i = beaconsToDelete.size() - 1; i >= 0; i--) {
            BeaconBase beaconBase = beaconsToDelete.get(i);
            beaconBase.getBeacons().deleteAllFromRealm();
            beaconBase.deleteFromRealm();
        }
    });
}

虽然要多用一点，但您也可以这样做：

public class BeaconBase extends RealmObject {

    @PrimaryKey
    private Integer checkInID;

    @SerializedName("beacons")
    @Expose
    private RealmList<BeaconData> beacons;
}

public class BeaconData extends RealmObject {

    @SerializedName("scanId")
    @Expose
    private String scanId;

    @SerializedName("distance")
    @Expose
    private String distance;

    @LinkingObjects("beacons")
    private final RealmResults<BeaconBase> beaconDataOf = null;
}

try(Realm r = Realm.getDefaultInstance)) {
    r.executeTransaction((realm) -> {
        realm.where(BeaconBase.class)./*query here*/.findAll().deleteAllFromRealm();
        realm.where(BeaconData.class).isEmpty("beaconDataOf").findAll().deleteAllFromRealm();
    });
}

域以有效方式删除孤立对象

1 个答案: