The do command is only for queries that do not return a result.
Rather than giving you some of my examples, I can address you to jeffa's excellent tutorial on HTML::Template.
It tells you exactly how to do what you need using selectall_arrayref.

update (I hit the submit button instead of preview) :(
As for you last question, I am not sure I got it correctly, but to get all the values from a column you can use this (untested) paradigm:

my $column = "rent";
my $rows= dbh->selectall_arrayref(qq{SELECT DISTINCT $column FROM owne
+r});
for (@$rows) {
    print "@$_\n"
};
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