gistfile1.txt

$posted = DB::select("
            SELECT 
                a.id,
                (
                    SELECT COUNT(*) FROM
                    pc_attachment_files as c 
                    WHERE c.detail_id = b.id
                ) as attachment_file_count
            FROM 
            pc_headers as a 
            LEFT JOIN pc_details as b on a.id = b.header_id
            WHERE 
                (b.attachment_file = ''
                OR b.attachment_file is null)
                and
                a.id = ?
        ",[$id]);