CRUD - Read - Java SDK

ProjectTask task = realm.where(ProjectTask.class).equalTo("_id", PRIMARY_KEY_VALUE.get()).findFirst();
Log.v("EXAMPLE", "Fetched object by primary key: " + task);

val task = realm.where(ProjectTask::class.java)
    .equalTo("_id", ObjectId.get()).findFirst()
Log.v("EXAMPLE", "Fetched object by primary key: $task")

RealmQuery<ProjectTask> tasksQuery = realm.where(ProjectTask.class);
RealmQuery<Project> projectsQuery = realm.where(Project.class);

val tasksQuery = realm.where(ProjectTask::class.java)
val projectsQuery = realm.where(Project::class.java)

RealmQuery<ProjectTask> tasksQuery = realm.where(ProjectTask.class);
Log.i("EXAMPLE", "High priority tasks: " + tasksQuery.greaterThan("priority", 5).count());
Log.i("EXAMPLE", "Just-started or short tasks: " + tasksQuery.between("progressMinutes", 1, 10).count());
Log.i("EXAMPLE", "Unassigned tasks: " + tasksQuery.isNull("assignee").count());
Log.i("EXAMPLE", "Ali or Jamie's tasks: " + tasksQuery.in("assignee", new String[]{"Ali", "Jamie"}).count());

val tasksQuery = realm.where(ProjectTask::class.java)
Log.i(
    "EXAMPLE", "High priority tasks: " + tasksQuery.greaterThan(
        "priority",
        5
    ).count()
)
Log.i(
    "EXAMPLE", "Just-started or short tasks: " + tasksQuery.between(
        "progressMinutes",
        1,
        10
    ).count()
)
Log.i(
    "EXAMPLE",
    "Unassigned tasks: " + tasksQuery.isNull("assignee").count()
)
Log.i(
    "EXAMPLE", "Ali or Jamie's tasks: " + tasksQuery.`in`(
        "assignee", arrayOf(
            "Ali",
            "Jamie"
        )
    ).count()
)

RealmQuery<Project> projectsQuery = realm.where(Project.class);
RealmResults<Project> results = projectsQuery.sort("name", Sort.DESCENDING).findAll();

val projectsQuery = realm.where(Project::class.java)
val results = projectsQuery.sort("name", Sort.DESCENDING).findAll()

import org.bson.types.ObjectId;
import io.realm.RealmObject;
import io.realm.annotations.PrimaryKey;
public class Human extends RealmObject {
    @PrimaryKey
    private ObjectId _id = new ObjectId();
    private String name;
    private Cat cat; 
    public Human(String name) {
        this.name = name;
    }
    public Human() {
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Cat getCat() {
        return cat;
    }
    public void setCat(Cat cat) {
        this.cat = cat;
    }
    public ObjectId get_id() {
        return _id;
    }
}

import org.bson.types.ObjectId;
import io.realm.RealmObject;
import io.realm.RealmResults;
import io.realm.annotations.LinkingObjects;
import io.realm.annotations.PrimaryKey;
public class Cat extends RealmObject {
    @PrimaryKey
    private ObjectId _id = new ObjectId();
    private String name = null;
    @LinkingObjects("cat") 
    private final RealmResults<Human> owner = null; 
    public Cat(String name) {
        this.name = name;
    }
    public Cat() {
    }
    public ObjectId get_id() {
        return _id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public RealmResults<Human> getOwner() {
        return owner;
    }
}

SyncConfiguration config = new SyncConfiguration.Builder(app.currentUser(), PARTITION)
        .allowQueriesOnUiThread(true)
        .allowWritesOnUiThread(true)
        .build();
Realm.getInstanceAsync(config, new Realm.Callback() {
    @Override
    public void onSuccess(Realm realm) {
        Log.v(
                "EXAMPLE",
                "Successfully opened a realm with reads and writes allowed on the UI thread."
        );
        realm.executeTransaction(transactionRealm -> {
            Human owner = transactionRealm.where(Human.class).equalTo("cat.name", "bucky").findFirst();
            Cat cat = owner.getCat();
            Log.v("EXAMPLE", "Queried for humans with cats named 'bucky'. Found " + owner.getName() + ", who owns " + cat.getName());
        });
        realm.close();
    }
});

import io.realm.RealmObject
import io.realm.annotations.PrimaryKey
import org.bson.types.ObjectId
open class Person(var name : String? = null) : RealmObject() {
    @PrimaryKey
    var _id : ObjectId = ObjectId()
    var dog: Dog? = null 
}

import io.realm.RealmObject
import io.realm.RealmResults
import io.realm.annotations.LinkingObjects
import io.realm.annotations.PrimaryKey
import org.bson.types.ObjectId
open class Dog(var name : String? = null): RealmObject() {
    @PrimaryKey
    var _id : ObjectId = ObjectId()
    @LinkingObjects("dog") 
    val owner: RealmResults<Person>? = null 
}

val config = SyncConfiguration.Builder(app.currentUser(), PARTITION)
    .allowQueriesOnUiThread(true)
    .allowWritesOnUiThread(true)
    .build()
Realm.getInstanceAsync(config, object : Realm.Callback() {
    override fun onSuccess(realm: Realm) {
        Log.v(
            "EXAMPLE",
            "Successfully opened a realm with reads and writes allowed on the UI thread."
        )
        realm.executeTransaction { transactionRealm ->
            val owner = transactionRealm.where<Person>().equalTo("dog.name", "henry").findFirst()
            val dog = owner?.dog
            Log.v("EXAMPLE", "Queried for people with dogs named 'henry'. Found $owner, owner of $dog")
        }
        realm.close()
    }
})

RealmQuery<ProjectTask> tasksQuery = realm.where(ProjectTask.class);
/*
Aggregate operators do not support dot-notation, so you
cannot directly operate on a property of all of the objects
in a collection property.
You can operate on a numeric property of the top-level
object, however:
*/
Log.i("EXAMPLE", "Tasks average priority: " + tasksQuery.average("priority"));

val tasksQuery = realm.where(ProjectTask::class.java)
/*
Aggregate operators do not support dot-notation, so you
cannot directly operate on a property of all of the objects
in a collection property.
You can operate on a numeric property of the top-level
object, however:
*/Log.i("EXAMPLE", "Tasks average priority: " + tasksQuery.average("priority"))