I think the only piece you are missing is returning the records. you can do this a number or ways. the simplest would be to push() the $ret value onto an array. then return the array at the end of your subroutine. Here is a simple example of how I have done it in the past.

while (@row = $sth->fetchrow) {
  if (@row > 1) {
    push(@ret,[@row]);
  }
  else  {
    push(@ret,@row);
  }
}

$sth->finish;
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Here I push the entire contents of the fetched rows.