Drupal(.module file)
Change 

$content=db_query("SELECT entity_id FROM {field_data_field_category_status}")-&gt;fetchField();
$content.='';


to

$records = db_query("SELECT entity_id FROM {field_data_field_category_status}")-&gt;fetchCol();
$content = implode('&lt;br /&gt;', $records);


At the moment you're just getting the first record from the result set, not all of them.

As a side note, going directly into field tables isn't the best idea. Have a look at EntityFieldQuery for an alternative.