#!/usr/bin/perl -Tw
use strict;

my @select_array = ('column1', 'column2', 'column3');
my @where_array = ('something = 1', 'somethig2 > 30'); 

my $select_clause = join(', ',@select_array);
my $where_clause  = join(' and ',@where_array);
my $sql = "SELECT $select_clause FROM table WHERE $where_clause";

print "SQL = '$sql'\n";