updated the test to not break other tests.

models/gnatEmail.php

+<?php
+class gnatEmail extends Doctrine_Record 
+{
+    public function setTableDefinition() 
+    {
+        $this->hasColumn('address', 'string', 150);
+    }
+    
+    
+}

models/gnatUser.php

@@ -7,13 +7,13 @@ class gnatUser extends Doctrine_Record
     public function setTableDefinition() 
     {
         $this->hasColumn('name', 'string', 150);
-        $this->hasColumn('email_id', 'integer', 10, array (  'unique' => true,));
+        $this->hasColumn('foreign_id', 'integer', 10, array (  'unique' => true,));
     }
     
     public function setUp()
     {
         parent::setUp();
-        $this->ownsOne('Email', array('local'=>'email_id','foreign'=>'id','onDelete'=>'CASCADE'));        
+        $this->ownsOne('gnatEmail as Email', array('local'=>'foreign_id','foreign'=>'id','onDelete'=>'CASCADE'));        
     }
     
 }

tests/Relation/OneToOneTestCase.php

@@ -36,7 +36,7 @@ class Doctrine_Relation_OneToOne_TestCase extends Doctrine_UnitTestCase
     { }
     public function prepareTables() 
     { 
-        $this->tables = array('gnatUser','Email','Entity','Record_City', 'Record_Country', 'SelfRefTest');
+        $this->tables = array('gnatUser','gnatEmail','Email','Entity','Record_City', 'Record_Country', 'SelfRefTest');
         
         parent::prepareTables();
     }
@@ -90,14 +90,14 @@ class Doctrine_Relation_OneToOne_TestCase extends Doctrine_UnitTestCase
     {
         $user = new gnatUser();
         $user->name = "test";
-        $email = new Email();
-        $email->address = "test@test.com";
+        $email = new gnatEmail();
+        $email->address = "test3@test.com";
         $user->Email = $email;
         $user->save();
-        $this->assertTrue($user->Email instanceOf Email);
-        $this->assertTrue($user->email_id != 0);
-        $this->assertTrue($user->email_id != null);
-        $this->assertTrue($user->email_id == $user->Email->id);
+        $this->assertTrue($user->Email instanceOf gnatEmail);
+        $this->assertTrue($user->foreign_id != 0);
+        $this->assertTrue($user->foreign_id != null);
+        $this->assertTrue($user->foreign_id == $user->Email->id);
         
     }
 }