diff --git a/framework/yii/ar/ActiveRelationTrait.php b/framework/yii/ar/ActiveRelationTrait.php
index 350718d..5d49641 100644
--- a/framework/yii/ar/ActiveRelationTrait.php
+++ b/framework/yii/ar/ActiveRelationTrait.php
@@ -97,13 +97,13 @@ trait ActiveRelationTrait
 
 		if ($this->via instanceof self) {
 			// via pivot table
-			/** @var ActiveRelation $viaQuery */
+			/** @var ActiveRelationTrait $viaQuery */
 			$viaQuery = $this->via;
 			$viaModels = $viaQuery->findPivotRows($primaryModels);
 			$this->filterByModels($viaModels);
 		} elseif (is_array($this->via)) {
 			// via relation
-			/** @var ActiveRelation $viaQuery */
+			/** @var ActiveRelationTrait $viaQuery */
 			list($viaName, $viaQuery) = $this->via;
 			$viaQuery->primaryModel = null;
 			$viaModels = $viaQuery->findWith($viaName, $primaryModels);
diff --git a/tests/unit/framework/data/ActiveDataProviderTest.php b/tests/unit/framework/data/ActiveDataProviderTest.php
index 3b445e0..4e4ca77 100644
--- a/tests/unit/framework/data/ActiveDataProviderTest.php
+++ b/tests/unit/framework/data/ActiveDataProviderTest.php
@@ -10,6 +10,8 @@ namespace yiiunit\framework\data;
 use yii\data\ActiveDataProvider;
 use yii\db\Query;
 use yiiunit\data\ar\ActiveRecord;
+use yiiunit\data\ar\Customer;
+use yiiunit\data\ar\Item;
 use yiiunit\framework\db\DatabaseTestCase;
 use yiiunit\data\ar\Order;
 
@@ -18,6 +20,7 @@ use yiiunit\data\ar\Order;
  * @since 2.0
  *
  * @group data
+ * @group db
  */
 class ActiveDataProviderTest extends DatabaseTestCase
 {
@@ -35,6 +38,8 @@ class ActiveDataProviderTest extends DatabaseTestCase
 		$orders = $provider->getModels();
 		$this->assertEquals(3, count($orders));
 		$this->assertTrue($orders[0] instanceof Order);
+		$this->assertTrue($orders[1] instanceof Order);
+		$this->assertTrue($orders[2] instanceof Order);
 		$this->assertEquals([1, 2, 3], $provider->getKeys());
 
 		$provider = new ActiveDataProvider([
@@ -47,6 +52,75 @@ class ActiveDataProviderTest extends DatabaseTestCase
 		$this->assertEquals(2, count($orders));
 	}
 
+	public function testActiveRelation()
+	{
+		/** @var Customer $customer */
+		$customer = Customer::find(2);
+		$provider = new ActiveDataProvider([
+			'query' => $customer->getOrders(),
+		]);
+		$orders = $provider->getModels();
+		$this->assertEquals(2, count($orders));
+		$this->assertTrue($orders[0] instanceof Order);
+		$this->assertTrue($orders[1] instanceof Order);
+		$this->assertEquals([2, 3], $provider->getKeys());
+
+		$provider = new ActiveDataProvider([
+			'query' => $customer->getOrders(),
+			'pagination' => [
+				'pageSize' => 1,
+			]
+		]);
+		$orders = $provider->getModels();
+		$this->assertEquals(1, count($orders));
+	}
+
+	public function testActiveRelationVia()
+	{
+		/** @var Order $order */
+		$order = Order::find(2);
+		$provider = new ActiveDataProvider([
+			'query' => $order->getItems(),
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(3, count($items));
+		$this->assertTrue($items[0] instanceof Item);
+		$this->assertTrue($items[1] instanceof Item);
+		$this->assertTrue($items[2] instanceof Item);
+		$this->assertEquals([3, 4, 5], $provider->getKeys());
+
+		$provider = new ActiveDataProvider([
+			'query' => $order->getItems(),
+			'pagination' => [
+				'pageSize' => 2,
+			]
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(2, count($items));
+	}
+
+	public function testActiveRelationViaTable()
+	{
+		/** @var Order $order */
+		$order = Order::find(1);
+		$provider = new ActiveDataProvider([
+			'query' => $order->getBooks(),
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(2, count($items));
+		$this->assertTrue($items[0] instanceof Item);
+		$this->assertTrue($items[1] instanceof Item);
+
+		$provider = new ActiveDataProvider([
+			'query' => $order->getBooks(),
+			'pagination' => [
+				'pageSize' => 1,
+			]
+		]);
+		$items = $provider->getModels();
+		$this->assertEquals(1, count($items));
+	}
+
 	public function testQuery()
 	{
 		$query = new Query;
diff --git a/tests/unit/framework/db/ActiveRecordTest.php b/tests/unit/framework/db/ActiveRecordTest.php
index d0d2f12..f96f2d3 100644
--- a/tests/unit/framework/db/ActiveRecordTest.php
+++ b/tests/unit/framework/db/ActiveRecordTest.php
@@ -119,10 +119,19 @@ class ActiveRecordTest extends DatabaseTestCase
 	{
 		/** @var Customer $customer */
 		$customer = Customer::find(2);
+		$this->assertFalse($customer->isRelationPopulated('orders'));
 		$orders = $customer->orders;
+		$this->assertTrue($customer->isRelationPopulated('orders'));
 		$this->assertEquals(2, count($orders));
+		$this->assertEquals(1, count($customer->populatedRelations));
 
+		/** @var Customer $customer */
+		$customer = Customer::find(2);
+		$this->assertFalse($customer->isRelationPopulated('orders'));
 		$orders = $customer->getOrders()->where('id=3')->all();
+		$this->assertFalse($customer->isRelationPopulated('orders'));
+		$this->assertEquals(0, count($customer->populatedRelations));
+
 		$this->assertEquals(1, count($orders));
 		$this->assertEquals(3, $orders[0]->id);
 	}
@@ -131,8 +140,15 @@ class ActiveRecordTest extends DatabaseTestCase
 	{
 		$customers = Customer::find()->with('orders')->all();
 		$this->assertEquals(3, count($customers));
+		$this->assertTrue($customers[0]->isRelationPopulated('orders'));
+		$this->assertTrue($customers[1]->isRelationPopulated('orders'));
 		$this->assertEquals(1, count($customers[0]->orders));
 		$this->assertEquals(2, count($customers[1]->orders));
+
+		$customer = Customer::find()->with('orders')->one();
+		$this->assertTrue($customer->isRelationPopulated('orders'));
+		$this->assertEquals(1, count($customer->orders));
+		$this->assertEquals(1, count($customer->populatedRelations));
 	}
 
 	public function testFindLazyVia()
diff --git a/tests/unit/framework/db/QueryTest.php b/tests/unit/framework/db/QueryTest.php
index a48d719..77c1ac0 100644
--- a/tests/unit/framework/db/QueryTest.php
+++ b/tests/unit/framework/db/QueryTest.php
@@ -86,19 +86,19 @@ class QueryTest extends DatabaseTestCase
 	{
 		$query = new Query;
 		$query->orderBy('team');
-		$this->assertEquals(['team' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC], $query->orderBy);
 
 		$query->addOrderBy('company');
-		$this->assertEquals(['team' => false, 'company' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC], $query->orderBy);
 
 		$query->addOrderBy('age');
-		$this->assertEquals(['team' => false, 'company' => false, 'age' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC, 'age' => SORT_ASC], $query->orderBy);
 
-		$query->addOrderBy(['age' => true]);
-		$this->assertEquals(['team' => false, 'company' => false, 'age' => true], $query->orderBy);
+		$query->addOrderBy(['age' => SORT_DESC]);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_ASC, 'age' => SORT_DESC], $query->orderBy);
 
 		$query->addOrderBy('age ASC, company DESC');
-		$this->assertEquals(['team' => false, 'company' => true, 'age' => false], $query->orderBy);
+		$this->assertEquals(['team' => SORT_ASC, 'company' => SORT_DESC, 'age' => SORT_ASC], $query->orderBy);
 	}
 
 	public function testLimitOffset()
diff --git a/tests/unit/framework/db/cubrid/CubridActiveDataProviderTest.php b/tests/unit/framework/db/cubrid/CubridActiveDataProviderTest.php
new file mode 100644
index 0000000..191442a
--- /dev/null
+++ b/tests/unit/framework/db/cubrid/CubridActiveDataProviderTest.php
@@ -0,0 +1,14 @@
+<?php
+namespace yiiunit\framework\db\cubrid;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group cubrid
+ * @group data
+ */
+class CubridActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'cubrid';
+}
diff --git a/tests/unit/framework/db/mssql/MssqlActiveDataProviderTest.php b/tests/unit/framework/db/mssql/MssqlActiveDataProviderTest.php
new file mode 100644
index 0000000..001b660
--- /dev/null
+++ b/tests/unit/framework/db/mssql/MssqlActiveDataProviderTest.php
@@ -0,0 +1,14 @@
+<?php
+namespace yiiunit\framework\db\mssql;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group mssql
+ * @group data
+ */
+class MssqlActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'sqlsrv';
+}
diff --git a/tests/unit/framework/db/pgsql/PostgreSQLActiveDataProviderTest.php b/tests/unit/framework/db/pgsql/PostgreSQLActiveDataProviderTest.php
new file mode 100644
index 0000000..674b564
--- /dev/null
+++ b/tests/unit/framework/db/pgsql/PostgreSQLActiveDataProviderTest.php
@@ -0,0 +1,14 @@
+<?php
+namespace yiiunit\framework\db\pgsql;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group pgsql
+ * @group data
+ */
+class PostgreSQLActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'pgsql';
+}
diff --git a/tests/unit/framework/db/sqlite/SqliteActiveDataProviderTest.php b/tests/unit/framework/db/sqlite/SqliteActiveDataProviderTest.php
new file mode 100644
index 0000000..660b14d
--- /dev/null
+++ b/tests/unit/framework/db/sqlite/SqliteActiveDataProviderTest.php
@@ -0,0 +1,14 @@
+<?php
+namespace yiiunit\framework\db\sqlite;
+
+use yiiunit\framework\data\ActiveDataProviderTest;
+
+/**
+ * @group db
+ * @group sqlite
+ * @group data
+ */
+class SqliteActiveDataProviderTest extends ActiveDataProviderTest
+{
+	public $driverName = 'sqlite';
+}