How can I tidy multiple if condition for readability?

For instance,

```
if( $key != 'pg_id' && $key != 'pg_tag' && $key != 'pg_user'  )

```

This confuses me when the items in that condition grow longer. 

It was used in this kind of situation below - `foreach()`,

```
$editable_fields = array(
    'pg_id',
    'pg_url',
    'pg_title',
    'pg_subtitle',
    'pg_description',
    'pg_introduction',
    'pg_content_1',
    'pg_content_2',
    'pg_content_3',
    'pg_content_4',
    'pg_backdate',
    'pg_highlight',
    'pg_hide',
    'pg_cat_id',
    'ps_cat_id',
    'parent_id',
    'tmp_id',
    'usr_id'
);

$sql_pattern = array();

foreach( $editable_fields as $key )
{
    if( $key != 'pg_id' && $key != 'pg_tag' && $key != 'pg_user'  ) $sql_pattern[] = "$key = ?";
}

```

I was thinking using [switch](https://stackoverflow.com/questions/6906603/how-to-convert-if-condition-to-switch-method) but I think I was wrong!