I'm having trouble with fetchall_arrayref() giving a very nonsensical (to me) error. Here's a little test that demonstrates it. (I know fetching results 3 rows at a time is silly, but it's only a test.)

use DBI;
my $dbh = DBI->connect('dbi:mysql:test', 'test', 'test') or die;

$dbh->do($_) for (split /\s*;\s*/, <<'END_OF_SQL');
    drop table if exists foo;
    create table foo ( bar int );
    insert into foo set bar=5;
    insert into foo set bar=4;
    insert into foo set bar=7;
    insert into foo set bar=1;
    insert into foo set bar=3
END_OF_SQL

#####

my $sth = $dbh->prepare("select bar from foo") or die;
$sth->execute or die;

#                 $sth->fetchall_arrayref([0],   3)
while (my $rows = $sth->fetchall_arrayref(undef, 3)) {
  for (@$rows) {
    print "got @$_\n";
  }
  print "---\n";
}

__OUTPUT__
got 5
got 4
got 7
---
got 1
got 3
---
[download]

OK. This code runs fine (for me)! But if I change undef to [0] in the fetchall_arrayref() line, I get this output:

__OUTPUT__
DBD::mysql::st fetchall_arrayref failed: fetch() without execute() at 
+foo.pl line 23.
---
DBD::mysql::st fetchall_arrayref failed: fetch() without execute() at 
+foo.pl line 23.
---
[... ad infinitum ..]
[download]

What gives? The execute() is fine, and certainly is before the fetchall_arrayref() call. But some people even seem to get these errors with the undef in there! FWIW, I'm using DBI 1.38.

Since my query only returns one column, I should be able to use [0] as the first argument to fetchall_arrayref() to explicitly just fetch the one column. Right?

It's not a huge problem for me to fetch rows one at a time and avoid fetchall_*, but it would be kinda nice to use fetchall_*, as it seems to be the fastest way to get lots of a data.

Additional: It's not the infinite loop that bothers me so much -- that can be worked around. It's that with the [0] argument, the fetchall_arrayref() doesn't work at all and I can't get the query's results.

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