try making your sql statement like this

my $query = q{select distinct
            account,
            account_id,
            company,
            the_date
        from account_information
        where account_id = ?};

my $sth = $dbh->prepare($query);

$sth->execute($_);
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That way the quoting is handled by the dbd (if i'm not mistaken)

If you'd like to not use the q{} construct you can try this.

my $query = "select distinct
            account,
            account_id,
            company,
            the_date
        from account_information
        where account_id = ?";

my $sth = $dbh->prepare($query);

$sth->execute($dbh->quote($_));
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just some ideas and different ways I've prepared dbi queries for execution. If any of the methods I used aren't in your version of DBI, please know I wasn't trying to be rude. I'm just not familiar with DBI's history other that what I've used.

Hope some of this helps.