Re: OOP: How to construct multiple instances of a class at once

[runrig]

Here is an incomplete example:

sub new {
  my ($class, @ids) = @_;
  my @users;
  my $sql = "SELECT user_id, user_name FROM users WHERE user_id IN (" 
+. join(",", @ids) . ")";
  my $sth = $dbh->prepare($sql);
  $sth->execute();
  $sth->bind_cols(\my ($id, $name));
  while ( $sth->fetch() ) {
    push @users, bless({
      user_id   => $id,
      user_name => $name,
    }, $class);
  };
  return wantarray ? @users : $users[0];
}

The @ids should be scrubbed for Bobby Tables issues, but that is also the case in your original code.

[Tanktalus]

Scrubbing for Bobby Tables issues? No, the SQL needs to be written for those issues.

my $sql = 'SELECT user_id, user_name FROM users WHERE user_id IN (' . 
+join(',', ('?') x @ids) . ')';
#...
$sth->execute(@ids);

Especially since perl makes this so trivially easy, as compared to, say, C.

[runrig]

If the ids were strings, I might use map $dbh->quote($_), @ids, but since they're probably integers, validating that they're /^\d+$/ is probably good enough. Either is also easy.