my $queryID = "select id, name from studentTable";
my $sth_queryID = $dbh->prepare($queryID);
$sth_queryID->execute();

my @studentInfo;
while (my @row = $sth_queryID->fetchrow){
   push @studentInfo, @row;
}

$sth_queryID->finish;

##</code><code>##

foreach (@studentInfo_with_an_odd_index){
    my $studentID = $_;
    my $queryGrade = "select id from grades where 
    id = '$studentID' and grade = 'A'";
    $my sth_queryGrade->prepare($queryGrade);
    $sth_queryGrade->execute();

    while (my @g = $sth_queryGrade->fetchrow){
        print "<TR>";
        print "<TD>$g[0]</TD>";
        print "<TD>$student_name_for_this_id</TD>";
        print "</TR>";
    }
}

$sth_queryGrade->finish;
$dbh->disconnect;