diff --git a/dibi/libs/DibiConnection.php b/dibi/libs/DibiConnection.php
index 25a19a6..7c0d37e 100644
--- a/dibi/libs/DibiConnection.php
+++ b/dibi/libs/DibiConnection.php
@@ -239,6 +239,26 @@ class DibiConnection extends DibiObject
 
 
 
+	/**
+	 * Generates and returns SQL query.
+	 * @param  array|mixed      one or more arguments
+	 * @return string
+	 * @throws DibiException
+	 */
+	final public function sql($args)
+	{
+		$args = func_get_args();
+		$this->connect();
+		$trans = new DibiTranslator($this->driver);
+		if ($trans->translate($args)) {
+			return $trans->sql;
+		} else {
+			throw new DibiException('SQL translate error: ' . $trans->sql);
+		}
+	}
+
+
+
 	/**
 	 * Generates and prints SQL query.
 	 * @param  array|mixed  one or more arguments
diff --git a/dibi/libs/DibiFluent.php b/dibi/libs/DibiFluent.php
index 1359698..738cc36 100644
--- a/dibi/libs/DibiFluent.php
+++ b/dibi/libs/DibiFluent.php
@@ -122,6 +122,9 @@ class DibiFluent extends DibiObject
 			} elseif (is_string($arg) && preg_match('#^[a-z][a-z0-9_.]*$#i', $arg)) { // identifier
 				$args = array('%n', $arg);
 
+			} elseif ($arg instanceof self) {
+				$args = array_merge(array('('), $arg->_export(), array(')'));
+
 			} elseif (is_array($arg)) { // any array
 				if (isset(self::$modifiers[$clause])) {
 					$args = array(self::$modifiers[$clause], $arg);
@@ -383,14 +386,12 @@ class DibiFluent extends DibiObject
 
 
 	/**
-	 * Returns (highlighted) SQL query.
+	 * Returns SQL query.
 	 * @return string
 	 */
 	final public function __toString()
 	{
-		ob_start();
-		$this->test();
-		return ob_get_clean();
+		return $this->connection->sql($this->_export());
 	}
 
 }