PDO声明我丢失了代币，但我没有——这有什么问题吗?

所以我已经设法吐出(通过var_dump)以下内容:

// This is my whole select statement
string 'SELECT * FROM logs AS LOG WHERE ( LOG.DATE BETWEEN :startMonth AND :endMonth ) AND LOG.VALUE LIKE :filter ' (length=106)
// This is the database object (note the params)
object(Micro'Database)[1667]
  protected 'query' => string 'SELECT * FROM logs AS LOG WHERE ( LOG.DATE BETWEEN :startMonth AND :endMonth ) ' (length=79)
  protected 'params' => 
    array
      ':startMonth' => 
        object(DateTime)[1668]
          public 'date' => string '2014-06-01 00:00:00' (length=19)
          public 'timezone_type' => int 3
          public 'timezone' => string 'UTC' (length=3)
      ':endMonth' => 
        object(DateTime)[1671]
          public 'date' => string '2014-06-30 23:59:59' (length=19)
          public 'timezone_type' => int 3
          public 'timezone' => string 'UTC' (length=3)
      ':filter' => string '%"unit_id": 1030006431%' (length=23)

所以在查询中，我们看到我使用:startMonth, :endMonth和:filter，然后在参数中，我们看到我设置了相同的变量。所有东西都应该在那里。但显然不是:

'SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens'

呃…不，所有的代币都在那里。让我们看一下代码

public static function findByWildCard($unitId=null, $messageType=null, $filter=null, $month) {
    $sqlSelect = 'SELECT * ' .
                    'FROM logs AS LOG '.
                    'WHERE ( LOG.DATE BETWEEN :startMonth AND :endMonth ) ';

    // Connect to lazarus
    $query = self::connectToLazarus();
    // Start of the specified month. Eg. 2013-01-01 00:00:00
    $startMonth = 'DateTime::createFromFormat('Y-m-d H:i:s', $month.' 00:00:00');
    // End of the specified month. Eg. 2013-01-31 11:59:59
    $endMonth = clone $startMonth;
    $oneMonth = 'DateInterval::createFromDateString('1 month');
    $oneSecond = 'DateInterval::createFromDateString('1 second');
    $endMonth->add($oneMonth)->sub($oneSecond);
    // Get the results from the query
    $query->setQuery($sqlSelect)
        ->setParameter('startMonth', $startMonth)
        ->setParameter('endMonth', $endMonth);
    if (!empty($filter)) {
        $sqlSelect .= 'AND LOG.VALUE LIKE :filter ';
        $query->setParameter('filter', '%'.$filter.'%');
    }
    var_dump($query->getResult()); exit;
}

怎么回事?