Why is DBI returning a ref to a ref to a ref to a list? (code)

deprecated has asked for the wisdom of the Perl Monks concerning the following question:

I ran into something strange when using DBI today. I found that it was returning a reference to a reference to a reference to a list. Why is this? Am I using the wrong call?

my @rv = $dbh -> selectall_arrayref( $commands, undef, ( $query ) );

foreach my $value (@rv) {
  my @deref = @{ $value };
  foreach my $subval (@deref) {
    foreach my $ssval (@{$subval}) {
      print "$ssval";
      <>;
    }
  }
}
[download]

Thanks, bro dep.

--
Laziness, Impatience, Hubris, and Generosity.

Comment on Why is DBI returning a ref to a ref to a ref to a list? (code) Download Code

Replies are listed 'Best First'.
(boo) Re: Why is DBI returning a ref to a ref to a ref to a list? (code) by boo_radley (Parson) on Jun 12, 2001 at 22:44 UTC
regarding `my @rv = $dbh -> selectall_arrayref( $commands, undef, ( $query ) );` : @foo=$arrayref makes a one element array containing that reference. @foo=@{$arrayref} will probably do what you want. sample : `$bar=1; @foo=$bar; print @foo,"\n"; $bar=["this","is","an","arrayref"]; @foo=$bar; print @foo,"\n"; @foo=@{$bar}; print @foo,"\n"; $bar=&baz; @foo=@{$bar}; print @foo,"\n"; @foo=@{&baz}; print @foo,"\n"; sub baz { return["this","is","also","an","arrayref"]; }` [download] OK?	[reply] [d/l] [select]
Re: Why is DBI returning a ref to a ref to a ref to a list? (code) by runrig (Abbot) on Jun 12, 2001 at 22:40 UTC
From the DBI docs: `This utility method combines the prepare, execute, and fetchall_arrayref entries elsewhere in this document into a single call. It returns a reference to an array containing a reference to an array for each row of data fetched.` [download] Your '@rv' should be '$rv'. It is a reference to an array. Updated:Oops. Correction. and boo_radley beat me to it anyway :(	[reply] [d/l]