diff --git a/core/oqlclassnode.class.inc.php b/core/oqlclassnode.class.inc.php
index a57a1a0d2..a248b684d 100644
--- a/core/oqlclassnode.class.inc.php
+++ b/core/oqlclassnode.class.inc.php
@@ -21,18 +21,25 @@ class OQLClassNode
 	 *
 	 * @param QueryBuilderContext $oBuild
 	 * @param string $sNodeClass Current node class
-	 * @param string $sClassAlias Current node class alias
+	 * @param string $sNodeClassAlias Current node class alias
 	 * @param string $sOQLClassAlias Alias of the class requested in the filter (defaulted to $sClassAlias if null)
 	 */
-	public function __construct($oBuild, $sNodeClass, $sClassAlias, $sOQLClassAlias = null)
+	public function __construct($oBuild, $sNodeClass, $sNodeClassAlias, $sOQLClassAlias = null)
 	{
 		$this->sNodeClass = $sNodeClass;
-		$this->sNodeClassAlias = $sClassAlias;
+		if (empty($sNodeClassAlias))
+		{
+			$this->sNodeClassAlias = $oBuild->GetEmptyClassAlias();
+		}
+		else
+		{
+			$this->sNodeClassAlias = $sNodeClassAlias;
+		}
 		$this->aJoins = array();
 		$this->aExtKeys = array();
 		if (is_null($sOQLClassAlias))
 		{
-			$this->sOQLClassAlias = $sClassAlias;
+			$this->sOQLClassAlias = $this->sNodeClassAlias;
 		}
 		else
 		{
diff --git a/core/oqlclasstreebuilder.class.inc.php b/core/oqlclasstreebuilder.class.inc.php
index 9998726ac..0867150b6 100644
--- a/core/oqlclasstreebuilder.class.inc.php
+++ b/core/oqlclasstreebuilder.class.inc.php
@@ -29,6 +29,10 @@ class OQLClassTreeBuilder
 		$this->oDBObjetSearch = $oDBObjetSearch;
 		$this->sClass = $oDBObjetSearch->GetFirstJoinedClass();
 		$this->sClassAlias = $oDBObjetSearch->GetFirstJoinedClassAlias();
+		if (empty($this->sClassAlias))
+		{
+			$this->sClassAlias = $oBuild->GetEmptyClassAlias();
+		}
 		$this->oOQLClassNode = new OQLClassNode($oBuild, $this->sClass, $this->sClassAlias);
 	}
 
diff --git a/core/querybuildercontext.class.inc.php b/core/querybuildercontext.class.inc.php
index ac66f44c4..022487dd7 100644
--- a/core/querybuildercontext.class.inc.php
+++ b/core/querybuildercontext.class.inc.php
@@ -31,6 +31,7 @@ class QueryBuilderContext
 	protected $m_aModifierProperties;
 	protected $m_aSelectedClasses;
 	protected $m_aFilteredTables;
+	protected $m_sEmptyClassAlias;
 
 	public $m_oQBExpressions;
 
@@ -69,8 +70,14 @@ class QueryBuilderContext
 		// Add all the attribute of interest
 		foreach ($this->m_aSelectedClasses as $sClassAlias => $sClass)
 		{
+			$sTableAlias = $sClassAlias;
+			if (empty($sTableAlias))
+			{
+				$sTableAlias = $this->GenerateClassAlias("$sClass", $sClass);
+				$this->m_sEmptyClassAlias = $sTableAlias;
+			}
 			// default to the whole list of attributes + the very std id/finalclass
-			$this->m_oQBExpressions->AddSelect($sClassAlias.'id', new FieldExpression('id', $sClassAlias));
+			$this->m_oQBExpressions->AddSelect($sClassAlias.'id', new FieldExpression('id', $sTableAlias));
 			if (is_null($aAttToLoad) || !array_key_exists($sClassAlias, $aAttToLoad))
 			{
 				$sSelectedClass = $this->GetSelectedClass($sClassAlias);
@@ -86,7 +93,7 @@ class QueryBuilderContext
 				{
 					continue;
 				}
-				$oExpression = new FieldExpression($sAttCode, $sClassAlias);
+				$oExpression = new FieldExpression($sAttCode, $sTableAlias);
 				$this->m_oQBExpressions->AddSelect($sClassAlias.$sAttCode, $oExpression);
 			}
 		}
@@ -140,4 +147,14 @@ class QueryBuilderContext
 	{
 		return $this->m_aFilteredTables;
 	}
+
+	/**
+	 * @return string
+	 */
+	public function GetEmptyClassAlias()
+	{
+		return $this->m_sEmptyClassAlias;
+	}
+
+
 }
diff --git a/test/core/OQLToSQLAllClassesTest.php b/test/core/OQLToSQLAllClassesTest.php
index 3b9d334c3..71bb6baea 100644
--- a/test/core/OQLToSQLAllClassesTest.php
+++ b/test/core/OQLToSQLAllClassesTest.php
@@ -13,6 +13,7 @@ define('PRECISION', 2);
 
 use CMDBSource;
 use Combodo\iTop\Test\UnitTest\ItopDataTestCase;
+use DBObjectSearch;
 use DBSearch;
 use MetaModel;
 use SetupUtils;
@@ -35,6 +36,15 @@ class OQLToSQLAllCLassesTest extends ItopDataTestCase
 		SetupUtils::builddir(APPROOT.'log/test/OQLToSQL');
 	}
 
+	public function testEmptyAlias()
+	{
+		$oFilter = new DBObjectSearch('Organization', '');
+		$oFilter->AllowAllData();
+		$sSQL = $oFilter->MakeSelectQuery();
+		CMDBSource::Query($sSQL);
+		$this->assertTrue(true);
+	}
+
 	private function GetPreviousTestResult($sTestId)
 	{
 		$sResultFile = APPROOT.'log/test/OQLToSQL/'.$sTestId.'.txt';