I can't add the code snippet in the comment to the other answer but here goes; FetchrowArray() will return a list of columns for one row of the result, so you'd have to iterate over it like below; as pointed out. And if you want to add all results to an array, just use push.
$Self->{DBObject}->Prepare(
SQL => "SELECT id FROM table",
Limit => 10
);
my @IDs;
while ( my @Row = $Self->{DBObject}->FetchrowArray() ) {
push @IDs, $Row[0];
}