my $queries = (
"SELECT * FROM or_mod;"
"SELECT * FROM or_mod WHERE upper(component) = upper(?)";
"SELECT * FROM or_mod WHERE upper(env)       = upper(?)";
"SELECT * FROM or_mod WHERE upper(component) = upper(?) AND 
                           upper(env)       = upper(?)";
);
my $sth; my @bind;
if (defined($query{env}) &&(defined $query{component}) {
   $sth = $dbh->prepare($queries->[3]);
   $sth->execute($query{component}, $query{env});
} elsif ( defined ($query{env}) ) { 
   $sth = $dbh->prepare($queries->[2]);
   $sth->execute($query{env});
} elsif ( defined ($query{component}) ) {
   $sth = $dbh->prepare($queries->[1]);
   $sth->execute($query{component});
} else {
   $sth = $dbh->prepare($queries->[0]);
   $sth->execute;
}