#!/usr/bin/perl
use warnings;
use strict;

my $sql_var_hr;
$sql_var_hr->{col_name} = 'column_name';
my $sql = get_sql($sql_var_hr);


sub get_sql {
	my ($vars) = @_;
	my $sql;

	while (my $iline = <DATA>) {
            next if $iline =~ /^#/;
            $sql .= $iline;
	}
	print "pre_eval: $sql\n";
	eval '$sql = "' . $sql . '"' or warn $@;
	print "post_eval: $sql\n";
	return $sql;
}

__DATA__
select $vars->{col_name} from schema.table
select $$vars{col_name} from schema.table