Cast to array, fix #49

Author: nunomazer

src/Database/Connection.php

@@ -517,7 +517,7 @@ public function compileOffset($offset, $query, $bindings = array(), $me)
             $me->getFetchMode()
         )[0];
 
-        if (count($identity) === 0) {
+        if (count((array)$identity) === 0) {
             $queryString = $this->queryStringForPrimaries($from);
             $primaries = $this->getPdo()->query($queryString)->fetchAll(
                 $me->getFetchMode()