diff --git a/extensions/mongo/Command.php b/extensions/mongo/Command.php
index fcaf591..7a21177 100644
--- a/extensions/mongo/Command.php
+++ b/extensions/mongo/Command.php
@@ -8,6 +8,7 @@
 namespace yii\mongo;
 
 use \yii\base\Component;
+use Yii;
 
 /**
  * Class Command
@@ -23,10 +24,136 @@ class Command extends Component
 	public $db;
 
 	/**
-	 * Drop the current database
+	 * Drops the current database
 	 */
 	public function dropDb()
 	{
 		$this->db->db->drop();
 	}
+
+	/**
+	 * Drops the specified collection.
+	 * @param string $name collection name.
+	 */
+	public function dropCollection($name)
+	{
+		$collection = $this->db->getCollection($name);
+		$collection->drop();
+	}
+
+	/**
+	 * @param $collection
+	 * @param array $query
+	 * @param array $fields
+	 * @return \MongoCursor
+	 */
+	public function find($collection, $query = [], $fields = [])
+	{
+		$collection = $this->db->getCollection($collection);
+		return $collection->find($query, $fields);
+	}
+
+	/**
+	 * @param $collection
+	 * @param array $query
+	 * @param array $fields
+	 * @return array
+	 */
+	public function findAll($collection, $query = [], $fields = [])
+	{
+		$cursor = $this->find($collection, $query, $fields);
+		$result = [];
+		foreach ($cursor as $data) {
+			$result[] = $data;
+		}
+		return $result;
+	}
+
+	/**
+	 * Inserts new data into collection.
+	 * @param string $collection name of the collection.
+	 * @param array|object $data data to be inserted.
+	 * @param array $options list of options in format: optionName => optionValue.
+	 * @return \MongoId new record id instance.
+	 * @throws Exception on failure.
+	 */
+	public function insert($collection, $data, $options = [])
+	{
+		$token = 'Inserting data into ' . $collection;
+		Yii::info($token, __METHOD__);
+		try {
+			Yii::beginProfile($token, __METHOD__);
+			$collection = $this->db->getCollection($collection);
+			$this->tryResultError($collection->insert($data, $options));
+			Yii::endProfile($token, __METHOD__);
+			return is_array($data) ? $data['_id'] : $data->_id;
+		} catch (\Exception $e) {
+			Yii::endProfile($token, __METHOD__);
+			throw new Exception($e->getMessage(), (int)$e->getCode(), $e);
+		}
+	}
+
+	/**
+	 * Update the existing database data, otherwise insert this data
+	 * @param string $collection name of the collection.
+	 * @param array|object $data data to be updated/inserted.
+	 * @param array $options list of options in format: optionName => optionValue.
+	 * @return \MongoId updated/new record id instance.
+	 * @throws Exception on failure.
+	 */
+	public function save($collection, $data, $options = [])
+	{
+		$token = 'Saving data into ' . $collection;
+		Yii::info($token, __METHOD__);
+		try {
+			Yii::beginProfile($token, __METHOD__);
+			$collection = $this->db->getCollection($collection);
+			$this->tryResultError($collection->save($data, $options));
+			Yii::endProfile($token, __METHOD__);
+			return is_array($data) ? $data['_id'] : $data->_id;
+		} catch (\Exception $e) {
+			Yii::endProfile($token, __METHOD__);
+			throw new Exception($e->getMessage(), (int)$e->getCode(), $e);
+		}
+	}
+
+	/**
+	 * Removes data from the collection.
+	 * @param string $collection name of the collection.
+	 * @param array $criteria description of records to remove.
+	 * @param array $options list of options in format: optionName => optionValue.
+	 * @return boolean whether operation was successful.
+	 * @throws Exception on failure.
+	 */
+	public function remove($collection, $criteria = [], $options = [])
+	{
+		$token = 'Removing data from ' . $collection;
+		Yii::info($token, __METHOD__);
+		try {
+			Yii::beginProfile($token, __METHOD__);
+			$collection = $this->db->getCollection($collection);
+			$this->tryResultError($collection->remove($criteria, $options));
+			Yii::endProfile($token, __METHOD__);
+			return true;
+		} catch (\Exception $e) {
+			Yii::endProfile($token, __METHOD__);
+			throw new Exception($e->getMessage(), (int)$e->getCode(), $e);
+		}
+	}
+
+	/**
+	 * Checks if command execution result ended with an error.
+	 * @param mixed $result raw command execution result.
+	 * @throws Exception if an error occurred.
+	 */
+	protected function tryResultError($result)
+	{
+		if (is_array($result)) {
+			if (!empty($result['err'])) {
+				throw new Exception($result['errmsg'], (int)$result['code']);
+			}
+		} elseif (!$result) {
+			throw new Exception('Unknown error, use "w=1" option to enable error tracking');
+		}
+	}
 }
\ No newline at end of file
diff --git a/extensions/mongo/Connection.php b/extensions/mongo/Connection.php
index 2566f07..8158b15 100644
--- a/extensions/mongo/Connection.php
+++ b/extensions/mongo/Connection.php
@@ -9,7 +9,6 @@ namespace yii\mongo;
 
 use yii\base\Component;
 use yii\base\InvalidConfigException;
-use yii\db\Exception;
 use Yii;
 
 /**
@@ -102,12 +101,13 @@ class Connection extends Component
 				Yii::beginProfile($token, __METHOD__);
 				$options = $this->options;
 				$options['connect'] = true;
+				$options['db'] = $this->dbName;
 				$this->client = new \MongoClient($this->dsn, $options);
 				$this->db = $this->client->selectDB($this->dbName);
 				Yii::endProfile($token, __METHOD__);
 			} catch (\Exception $e) {
 				Yii::endProfile($token, __METHOD__);
-				throw new Exception($e->getMessage(), [], (int)$e->getCode(), $e);
+				throw new Exception($e->getMessage(), (int)$e->getCode(), $e);
 			}
 		}
 	}
diff --git a/extensions/mongo/Exception.php b/extensions/mongo/Exception.php
new file mode 100644
index 0000000..0687e48
--- /dev/null
+++ b/extensions/mongo/Exception.php
@@ -0,0 +1,25 @@
+<?php
+/**
+ * @link http://www.yiiframework.com/
+ * @copyright Copyright (c) 2008 Yii Software LLC
+ * @license http://www.yiiframework.com/license/
+ */
+
+namespace yii\mongo;
+
+/**
+ * Exception represents an exception that is caused by some Mongo-related operations.
+ *
+ * @author Paul Klimov <klimov.paul@gmail.com>
+ * @since 2.0
+ */
+class Exception extends \yii\base\Exception
+{
+	/**
+	 * @return string the user-friendly name of this exception
+	 */
+	public function getName()
+	{
+		return \Yii::t('yii', 'Mongo Exception');
+	}
+}
\ No newline at end of file
diff --git a/tests/unit/extensions/mongo/CommandTest.php b/tests/unit/extensions/mongo/CommandTest.php
new file mode 100644
index 0000000..c9621d1
--- /dev/null
+++ b/tests/unit/extensions/mongo/CommandTest.php
@@ -0,0 +1,96 @@
+<?php
+
+namespace yiiunit\extensions\mongo;
+
+/**
+ * @group mongo
+ */
+class CommandTest extends MongoTestCase
+{
+	protected function tearDown()
+	{
+		$this->dropCollection('customer');
+		parent::tearDown();
+	}
+
+	// Tests :
+
+	public function testInsert()
+	{
+		$command = $this->getConnection()->createCommand();
+		$data = [
+			'name' => 'customer 1',
+			'address' => 'customer 1 address',
+		];
+		$id = $command->insert('customer', $data);
+		$this->assertTrue($id instanceof \MongoId);
+		$this->assertNotEmpty($id->__toString());
+	}
+
+	/**
+	 * @depends testInsert
+	 */
+	public function testFindAll()
+	{
+		$command = $this->getConnection()->createCommand();
+		$data = [
+			'name' => 'customer 1',
+			'address' => 'customer 1 address',
+		];
+		$id = $command->insert('customer', $data);
+
+		$rows = $command->findAll('customer');
+		$this->assertEquals(1, count($rows));
+		$this->assertEquals($id, $rows[0]['_id']);
+	}
+
+	public function testSave()
+	{
+		$command = $this->getConnection()->createCommand();
+		$data = [
+			'name' => 'customer 1',
+			'address' => 'customer 1 address',
+		];
+		$id = $command->save('customer', $data);
+		$this->assertTrue($id instanceof \MongoId);
+		$this->assertNotEmpty($id->__toString());
+	}
+
+	/**
+	 * @depends testSave
+	 */
+	public function testUpdate()
+	{
+		$command = $this->getConnection()->createCommand();
+		$data = [
+			'name' => 'customer 1',
+			'address' => 'customer 1 address',
+		];
+		$newId = $command->save('customer', $data);
+
+		$updatedId = $command->save('customer', $data);
+		$this->assertEquals($newId, $updatedId, 'Unable to update data!');
+
+		$data['_id'] = $newId->__toString();
+		$updatedId = $command->save('customer', $data);
+		$this->assertEquals($newId, $updatedId, 'Unable to updated data by string id!');
+	}
+
+	/**
+	 * @depends testFindAll
+	 */
+	public function testRemove()
+	{
+		$command = $this->getConnection()->createCommand();
+		$data = [
+			'name' => 'customer 1',
+			'address' => 'customer 1 address',
+		];
+		$id = $command->insert('customer', $data);
+
+		$command->remove('customer', ['_id' => $id]);
+
+		$rows = $command->findAll('customer');
+		$this->assertEquals(0, count($rows));
+	}
+}
\ No newline at end of file
diff --git a/tests/unit/extensions/mongo/ConnectionTest.php b/tests/unit/extensions/mongo/ConnectionTest.php
index 11d2d0f..175a665 100644
--- a/tests/unit/extensions/mongo/ConnectionTest.php
+++ b/tests/unit/extensions/mongo/ConnectionTest.php
@@ -2,9 +2,11 @@
 
 namespace yiiunit\extensions\mongo;
 
-
 use yii\mongo\Connection;
 
+/**
+ * @group mongo
+ */
 class ConnectionTest extends MongoTestCase
 {
 	public function testConstruct()
@@ -38,7 +40,7 @@ class ConnectionTest extends MongoTestCase
 
 		$connection = new Connection;
 		$connection->dsn = 'unknown::memory:';
-		$this->setExpectedException('yii\db\Exception');
+		$this->setExpectedException('yii\mongo\Exception');
 		$connection->open();
 	}
 
diff --git a/tests/unit/extensions/mongo/MongoTestCase.php b/tests/unit/extensions/mongo/MongoTestCase.php
index 1b11bd1..a4f20ac 100644
--- a/tests/unit/extensions/mongo/MongoTestCase.php
+++ b/tests/unit/extensions/mongo/MongoTestCase.php
@@ -88,4 +88,15 @@ class MongoTestCase extends TestCase
 		$this->mongo = $db;
 		return $db;
 	}
+
+	/**
+	 * Drops the specified collection.
+	 * @param string $name collection name.
+	 */
+	protected function dropCollection($name)
+	{
+		if ($this->mongo) {
+			$this->mongo->getCollection($name)->drop();
+		}
+	}
 }
\ No newline at end of file