php, how to search and replace in mysql database?
foreach($rowset as $row) {
  $replacement=preg_replace('/<strong>(.)/','1<strong>',$row->fieldname,1);
  myDBCall('update mytable set myfield="'.$replacement.'" where someid='.$row->someid);
}

update `table` set `fieldname` = replace(`fieldname`,'string_to_find','string_to_replace_with')