diff --git a/framework/yii/bootstrap/Nav.php b/framework/yii/bootstrap/Nav.php
index 8e35010..8069699 100644
--- a/framework/yii/bootstrap/Nav.php
+++ b/framework/yii/bootstrap/Nav.php
@@ -27,13 +27,19 @@ use yii\helpers\Html;
  *         ),
  *         array(
  *             'label' => 'Dropdown',
- *             'dropdown' => array(
+ *             'items' => array(
  *                  array(
- *                      'label' => 'DropdownA',
+ *                      'label' => 'Level 1 -DropdownA',
  *                      'url' => '#',
+ *                      'items' => array(
+ *                          array(
+ *                              'label' => 'Level 2 -DropdownA',
+ *                              'url' => '#',
+ *                          ),
+ *                      ),
  *                  ),
  *                  array(
- *                      'label' => 'DropdownB',
+ *                      'label' => 'Level 1 -DropdownB',
  *                      'url' => '#',
  *                  ),
  *             ),
@@ -114,7 +120,7 @@ class Nav extends Widget
 		}
 		$label = $this->encodeLabels ? Html::encode($item['label']) : $item['label'];
 		$options = ArrayHelper::getValue($item, 'options', array());
-		$dropdown = ArrayHelper::getValue($item, 'dropdown');
+		$items = ArrayHelper::getValue($item, 'items');
 		$url = Html::url(ArrayHelper::getValue($item, 'url', '#'));
 		$linkOptions = ArrayHelper::getValue($item, 'linkOptions', array());
 
@@ -122,19 +128,19 @@ class Nav extends Widget
 			$this->addCssClass($options, 'active');
 		}
 
-		if ($dropdown !== null) {
+		if ($items !== null) {
 			$linkOptions['data-toggle'] = 'dropdown';
 			$this->addCssClass($options, 'dropdown');
 			$this->addCssClass($urlOptions, 'dropdown-toggle');
 			$label .= ' ' . Html::tag('b', '', array('class' => 'caret'));
-			if (is_array($dropdown)) {
-				$dropdown = Dropdown::widget(array(
-					'items' => $dropdown,
+			if (is_array($items)) {
+				$items = Dropdown::widget(array(
+					'items' => $items,
 					'clientOptions' => false,
 				));
 			}
 		}
 
-		return Html::tag('li', Html::a($label, $url, $linkOptions) . $dropdown, $options);
+		return Html::tag('li', Html::a($label, $url, $linkOptions) . $items, $options);
 	}
 }
diff --git a/framework/yii/db/pgsql/Schema.php b/framework/yii/db/pgsql/Schema.php
index bec1803..94f845f 100644
--- a/framework/yii/db/pgsql/Schema.php
+++ b/framework/yii/db/pgsql/Schema.php
@@ -73,7 +73,7 @@ class Schema extends \yii\db\Schema
 	);
 
 	/**
-	 * Creates a query builder for the MySQL database.
+	 * Creates a query builder for the PostgreSQL database.
 	 * @return QueryBuilder query builder instance
 	 */
 	public function createQueryBuilder()
@@ -143,14 +143,9 @@ class Schema extends \yii\db\Schema
 
 		$sql = <<<SQL
 select 
-	ct.conname as containst,
-	c.relname as table_name,
-	ns.nspname as table_schema,
-	current_database() as table_catalog,
 	(select string_agg(attname,',') attname from pg_attribute where attrelid=ct.conrelid and attnum = any(ct.conkey)) as columns,
 	fc.relname as foreign_table_name,
 	fns.nspname as foreign_table_schema,
-	current_database() as foreign_table_catalog,
 	(select string_agg(attname,',') attname from pg_attribute where attrelid=ct.confrelid and attnum = any(ct.confkey)) as foreign_columns
 from
 	pg_constraint ct 
@@ -169,7 +164,12 @@ SQL;
 		foreach ($constraints as $constraint) {
 			$columns = explode(',', $constraint['columns']);
 			$fcolumns = explode(',', $constraint['foreign_columns']);
-			$citem = array($constraint['foreign_table_name']);
+			if ($constraint['foreign_table_schema'] !== $this->defaultSchema) {
+				$foreignTable = $constraint['foreign_table_schema'] . '.' . $constraint['foreign_table_name'];
+			} else {
+				$foreignTable = $constraint['foreign_table_name'];
+			}
+			$citem = array($foreignTable);
 			foreach ($columns as $idx => $column) {
 				$citem[] = array($fcolumns[$idx] => $column);
 			}
@@ -243,10 +243,6 @@ ORDER BY
 SQL;
 
 		$columns = $this->db->createCommand($sql)->queryAll();
-		if (empty($columns)) {
-			return false;
-		}
-
 		foreach ($columns as $column) {
 			$column = $this->loadColumnSchema($column);
 			$table->columns[$column->name] = $column;