diff --git a/model/SqlDbDriver.php b/model/SqlDbDriver.php
index e555c19..83014c6 100644
--- a/model/SqlDbDriver.php
+++ b/model/SqlDbDriver.php
@@ -110,7 +110,7 @@ abstract class SqlDbDriver extends DbDriver
     {
         $ident = explode('.', $ident);
         foreach ($ident as &$segment) {
-            if (!preg_match('/(\?|:[A-z0-9_]+)/u', $segment)) {
+            if (!preg_match('/(\?|:[A-z][A-z0-9_]*+)/u', $segment)) {
                 $segment = $this->identifier_quote . $segment . $this->identifier_quote;
             }
         }