参数号无效

What am I missing with this SUPER simple example where the code has initially been generated by Zend 2 SQL\Update however I've grabbed the SQL to process the error manually:

  $data = array(
      'Title' => 'Mrs'
  );

  $str = '`Title` = :Title';

  $this->adapter->query("UPDATE `contacts` SET $str WHERE `ContactID` = 5",$data); 

This code has been working fine however have been updating columns etc and its suddenly stopped working but the above code looks like it should be fine?

Thanks

Antony

At first look, change

$data = array(
    'Title' => 'Mrs'
);

to

$data = array(
    ':Title' => 'Mrs'
);

That being said, I wonder why

WHERE `ContactID` = 5

doesnt have another placeholder...