Realm-java: Get all RealmObjects matching a list of values

[MGaetan89]

If I have a list of values, is there an easy way to get all the RealmObject where a certain field has one of the values in my list?

For example:

List<String> ids = Arrays.asList("id1", "id2", "id3"); // Or simply an array

realm.where(MyObject.class).in("myField", ids).findAll(); // Return all MyObject where myField is equal to "id1" or "id2" or "id3"

Or do I have to loop through those values and use beginGroup().or() [...] .endGroup()?

[cmelchior]

There is no easy way unfortunately, but we are tracking the feature request here: https://github.com/realm/realm-java/issues/841

Until then the way to do it would be:

RealmQuery<MyObject> query = realm.where(MyObject.class);
for (String id : ids) {
  query.or().equalTo("myField", id);
}
RealmResults<MyObject> results = query.findAll();

[MGaetan89]

Sorry for not searching first...
Thank you for your answer.

[meierjan]

@cmelchior I was looking for the same thing and came across your workaround. Should't it be query.or().equalTo("myField", id);?

[cmelchior]

@meierjan
Ups! Yes, you are right.

[Ghedeon]

@cmelchior
Proposed solution seems to be not generic enough, it crashes with java.lang.UnsupportedOperationException: Missing right-hand side of OR in case of one single id, since it results into realm.where(MyObject.class).or().equalTo("myField", id).findAll() I believe. You would need to check the first id separately.

Anyway, in() operator seems to be already implemented in latest versions, got confused by #841 which is still opened.

[Zhuinden]

public RealmQuery<E> in(String fieldName, String[] values) {
    if (values == null || values.length == 0) {
        throw new IllegalArgumentException(EMPTY_VALUES);
    }
    beginGroup().equalTo(fieldName, values[0]);
    for (int i = 1; i < values.length; i++) {
        or().equalTo(fieldName, values[i]);
    }
    return endGroup();
}

@Ghedeon This is the general solution