use parent property to fallback method call to the parent object

Author: c9s

src/Universal/Syntax/Conditions.php

@@ -61,6 +61,11 @@ public function __construct(array $exprs = array(), $parent = null)
         $this->parent = $parent;
     }
 
+    public function setParent($parent)
+    {
+        $this->parent = $parent;
+    }
+
     /**
      * http://dev.mysql.com/doc/refman/5.0/en/expressions.html.
      */

src/Universal/Traits/WhereTrait.php

@@ -21,7 +21,7 @@ trait WhereTrait
     public function where($expr = null, array $args = array())
     {
         if (!$this->where) {
-            $this->where = new Conditions();
+            $this->where = new Conditions([], $this);
         }
         if ($expr) {
             if (is_string($expr)) {
@@ -40,6 +40,7 @@ public function where($expr = null, array $args = array())
 
     public function setWhere(Conditions $where)
     {
+        $where->setParent($this);
         $this->where = $where;
     }
 
@@ -49,7 +50,7 @@ public function getWhere()
             return $this->where;
         }
 
-        return $this->where = new Conditions();
+        return $this->where = new Conditions([], $this);
     }
 
     public function buildWhereClause(BaseDriver $driver, ArgumentArray $args)