diff --git a/model/MongoDbCommand.php b/model/MongoDbCommand.php
index 663f73e..1becb44 100644
--- a/model/MongoDbCommand.php
+++ b/model/MongoDbCommand.php
@@ -18,15 +18,19 @@ class MongoCommandBuilder
 
     const REMOVE = 'Remove';
 
-    static public function factory($type)
+    static public function factory($type, $collection = null)
     {
         $class = ucfirst($type) . 'MongoCommand';
-        return new $class();
+        $command = new $class();
+        $command->setCollection($collection);
+        return $command;
     }
 }
 
 abstract class MongoDbCommand
 {
+    protected $collection;
+
     public function execute()
     {
         if ($this->checkParams()) {
@@ -38,17 +42,29 @@ abstract class MongoDbCommand
 
     public function bindParam($name, $value)
     {
-        $this->$name = $value;
+        if (property_exists($this, $name)) {
+            $this->$name = $value;
+        }
+        return $this;
+    }
+
+    public function setCollection($collection)
+    {
+        $this->collection = $collection;
         return $this;
     }
 
-    abstract protected  function concreteExecute();
+    abstract protected function concreteExecute();
 
     abstract protected function checkParams();
 }
 
 class FindMongoCommand extends MongoDbCommand
 {
+    protected $condition;
+
+    protected $fields;
+
     protected function concreteExecute()
     {
         return $this->collection->find($this->condition, $this->fields);
@@ -66,6 +82,10 @@ class FindMongoCommand extends MongoDbCommand
 
 class InsertMongoCommand extends MongoDbCommand
 {
+    protected $data;
+
+    protected $safe;
+
     protected function concreteExecute()
     {
         return $this->collection->insert($this->data, array('safe' => $this->safe));
@@ -83,6 +103,14 @@ class InsertMongoCommand extends MongoDbCommand
 
 class UpdateMongoCommand extends MongoDbCommand
 {
+    protected $condition;
+
+    protected $data;
+
+    protected $upsert;
+
+    protected $safe;
+
     protected function concreteExecute()
     {
         return $this->collection->update($this->condition, $this->data, array('upsert' => $this->upsert, 'safe' => $this->safe));
@@ -102,6 +130,10 @@ class UpdateMongoCommand extends MongoDbCommand
 
 class RemoveMongoCommand extends MongoDbCommand
 {
+    protected $condition;
+
+    protected $safe;
+
     protected function concreteExecute()
     {
         return $this->collection->remove($this->condition, array('safe' => $this->safe));
diff --git a/tests/model/MongoDbCommandTest.php b/tests/model/MongoDbCommandTest.php
index 1cc2973..a05a9bb 100644
--- a/tests/model/MongoDbCommandTest.php
+++ b/tests/model/MongoDbCommandTest.php
@@ -59,8 +59,8 @@ class MongoDbCommandTest extends PHPUnit_Framework_TestCase
     public function testFindCommand()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'bread'))->bindParam('fields', array());
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'bread'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(0, $result->count());
     }
@@ -72,22 +72,22 @@ class MongoDbCommandTest extends PHPUnit_Framework_TestCase
     public function testFindCommandNotAllParamsBinded()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'bread'));
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'bread'));
         $cmd->execute();
     }
 
     public function testInsertCommand()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT);
-        $cmd->bindParam('collection', $collection)
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT, $collection);
+        $cmd
                 ->bindParam('data', array('name' => 'insert'))
                 ->bindParam('safe', true);
         $this->assertArrayHasKey('n', $cmd->execute());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(1, $result->count());
     }
@@ -99,33 +99,33 @@ class MongoDbCommandTest extends PHPUnit_Framework_TestCase
     public function testInsertCommandNotAllParamsBinded()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT);
-        $cmd->bindParam('collection', $collection)->bindParam('data', array('name' => 'bread'));
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT, $collection);
+        $cmd->bindParam('data', array('name' => 'bread'));
         $cmd->execute();
     }
 
     public function testUpdateCommand()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT);
-        $cmd->bindParam('collection', $collection)
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT, $collection);
+        $cmd
                 ->bindParam('data', array('name' => 'insert'))
                 ->bindParam('safe', true);
         $this->assertArrayHasKey('n', $cmd->execute());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::UPDATE);
-        $cmd->bindParam('collection', $collection)
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::UPDATE, $collection);
+        $cmd
                 ->bindParam('condition', array('name' => 'insert'))
                 ->bindParam('data', array('$set' => array('name' => 'update')))
                 ->bindParam('upsert', false)
                 ->bindParam('safe', true);
         $this->assertArrayHasKey('n', $cmd->execute());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(0, $result->count());
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'update'))->bindParam('fields', array());
+        $cmd->bindParam('condition', array('name' => 'update'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(1, $result->count());
     }
@@ -137,33 +137,33 @@ class MongoDbCommandTest extends PHPUnit_Framework_TestCase
     public function testUpdateCommandNotAllParamsBinded()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::UPDATE);
-        $cmd->bindParam('collection', $collection)->bindParam('data', array('name' => 'bread'));
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::UPDATE, $collection);
+        $cmd->bindParam('data', array('name' => 'bread'));
         $cmd->execute();
     }
 
     public function testRemoveCommand()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT);
-        $cmd->bindParam('collection', $collection)
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::INSERT, $collection);
+        $cmd
                 ->bindParam('data', array('name' => 'insert'))
                 ->bindParam('safe', true);
         $this->assertArrayHasKey('n', $cmd->execute());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(1, $result->count());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::REMOVE);
-        $cmd->bindParam('collection', $collection)
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::REMOVE, $collection);
+        $cmd
                 ->bindParam('condition', array('name' => 'insert'))
                 ->bindParam('safe', true);
         $this->assertArrayHasKey('n', $cmd->execute());
 
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND);
-        $cmd->bindParam('collection', $collection)->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::FIND, $collection);
+        $cmd->bindParam('condition', array('name' => 'insert'))->bindParam('fields', array());
         $result = $cmd->execute();
         $this->assertEquals(0, $result->count());
     }
@@ -175,8 +175,7 @@ class MongoDbCommandTest extends PHPUnit_Framework_TestCase
     public function testRemoveCommandNotAllParamsBinded()
     {
         $collection = $this->driver->getCollection('items');
-        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::REMOVE);
-        $cmd->bindParam('collection', $collection);
+        $cmd = MongoCommandBuilder::factory(MongoCommandBuilder::REMOVE, $collection);
         $cmd->execute();
     }