Using php DateTime object in mysql query - zend-framework

Question

I'm trying to create a query that pulls information about sellers from my database, but only if their store has launched in the last 3 days. The easiest way I can think of to calculate the date for the query is using a new DateTime() object. When I output my code to test it, it's in the proper string for MySQL to query it with, but whenever I try to bind the variable, I get an error. I'm using Zend_Db to query, (PDO adapter)
action:
public function indexAction()
{
$dateMod = new DateTime();
$dateMod->modify('-2 days');
$dateMod->format('Y-m-d H:i:s');
// get sellers initialized in last 3 days
$sellerTable = new Application_Model_DbTable_Sellers();
$select = $sellerTable->select()->setIntegrityCheck(false);
$select->from(array('s' => 'seller'),array('sellerID', 'businessName'));
// select firstName, lastName, picture from user table, and businessName and sellerID from seller table.
$select->join(array('u' => 'user'), 's.userID = u.userID', array('firstName', 'lastName', 'picture'));
$select->where('s.active = 1 AND s.contentApproval = 1 AND s.paymentApproval = 1 AND s.featured = 1');
$select->where('s.launchDate > ?', $dateMod);
$select->order('s.launchDate DESC');
$newSellers = $sellerTable->fetchAll($select);
When I assign $dateMod to the view, it outputs the correct Y-m-d H:i:s format. But when I plug it into the query, I get the following error:
Message: SQLSTATE[42000]: Syntax error or access violation: 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') ORDER BY `b`.`launchDate` DESC' at line 2
If I hardcode a value into dateMod in the mysql timestamp format, the query works fine. How can I access just the string value of the timestamp in the DateTime object? getTimestamp returns a unix formatted timestamp, even after assigning a format.

Answer 1

The format() function returns the formatted date, so you need to assign that to a variable for use in the query:
$dateFormatted = $dateMod->format('Y-m-d H:i:s');
$select->where('s.launchDate > ?', $dateFormatted);