How to update content type field programmatically
It's better to use Drupa API to do that instead of missing with the database directly. you can use field_attach_update to update your field value

$node = node_load($nid);
$field = field_language('node', $node, 'field_your_field');
$node-&gt;field[$field_language][0]['value'] = 'Your New value';
field_attach_update('node', $node);