SELECT column1,column2,column3 FROM table WHERE column4=?";

##</code><code>##

 
SELECT ? FROM ? WHERE ?=? 

##</code><code>##

my $query = "SELECT column1,column2,column3 FROM table WHERE column4=?";
my $sth = $dbh->prepare($query);
$sth->execute($value_for_placeholder) or die $sth->errstr();
my $hash_ref = $sth->fetchrow_hashref();

# if its easier for you, you can dereference that hash_ref:
my %hash = %$hash_ref;