Doctrine inserting NULL values for undefined fields - doctrine-orm

Question

I don't know if this is a bug, but I am using Doctrine 2.3.0 and I found the persist/flush behaviour quite strange. I have a basic table:
------------------
| test |
------------------
| id INT | AI |
| field1 VARCHAR |
| field2 VARCHAR |
-----------------
When I create an entry by setting only field1:
$test = new Entities\test();
$test->setField1('foo');
$em->persist($test);
$em->flush();
Doctrine\DBAL\Logging\EchoSQLLogger tells me (which is confirmed by looking at the DB) that Doctrine performs the following query:
INSERT INTO test (field1, field2) VALUES (?, ?)
array(2) {
[1]=>
string(3) "foo"
[2]=>
NULL
}
As you can see, although I haven't set field2, Doctrine does put it in the insert statement with a NULL value.
I have that behaviour for all my entities, which is problematic because when doing inserts, my default DB values for fields I don't set are overwritten by NULL.
Is this the expected default behaviour of Doctrine, is there a way to turn that off (i.e. exclude fields I don't set from the INSERT statements)?
I should probably add that my entities were generated automatically with the reverse engineering, and that the declaration for one of the fields looks like this
/**
* #var string $field2
* // removing nullalble makes no diff.
* #ORM\Column(name="field2", type="string", length=45, nullable=true)
*/
private $field2;
/**
* Set field2
*
* #param string $field2
* #return Test
*/
public function setField2($field2)
{
$this->field2 = $field2;
return $this;
}

Answer 1

I suppose this is default behaviour, as it could be treated logical to create a full record in one INSERT statement. But I could be mistaking. Having some kind of #ORM\Column(type="boolean", columnDefinition="TINYINT(1) NULL DEFAULT 0") could be treated as a hack, but solution. I advise you to review database record insertion logic.