use strict;
  use DBI;
  # make the connection the way you have shown
  my @resultrow = ();
  my $resultref = $dbh->selectrow_arrayref("select ID from study 
    where NAME='$unique_search_string_here'");
  if (ref($resultref) eq 'ARRAY') {
    @resultrow = @{$resultref};
    # do something with $resultrow[0]
  }
  else {
    # check for error in $DBI::errstr, etc.
  }