Try to avoid nested queries by storing the results from the first query in a hash or array. Then loop over that structure to do more queries. You can also reuse those statement handles and variables. This example avoids the nesting and might be further improved with joins, or a more normalized database. 
my $sth = $dbh->prepare_cached(<<SQL);
Select id, username From members
SQL

$sth->execute();
$sth->bind_columns(\my($id,$username));

my $user;

while ($sth->fetch) {
  $user->{$id} = $username
}

for my $id (keys %$user) {
  $sth = $dbh->prepare_cached(q{SELECT COUNT(*) From Results WHERE use
+r_id = ? AND read = ?});
  $sth->execute($id,2);
  $sth->bind_columns(\my($count));
  $sth->fetch;
  print $count;

  $sth = $dbh->prepare_cached(q{SELECT COUNT(*) From Results WHERE use
+r_id = ? AND read = ?});
  $sth->execute($id,3);
  $sth->bind_columns(\$count);
  $sth->fetch;
  print $count;
}

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In reply to Re^2: How many Select Querie is considered too much? by Anonymous Monk
in thread How many Select Querie is considered too much? by Anonymous Monk

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