#! perl -slw
use strict;

$/ = ""; # Set paragraph mode (see Perlvar:$/)
while( <DATA>) {
	m[(\w+)\s+as]i and print "'$1'";
}

__DATA__
  create   view V_PAID_USERS as
  select * from users u, subcription s
  where u.user_id=s.user_id and s.balance =< 0;

  CREATE  OR REPLACE VIEW V_OVERDUE
  AS select *
  from
  users u,
  subscription s
  where u.user_id=s.user_id and s.duedate > 60;

  create TABLE UNPAID_USERS as
  select * from users u, subcription s where u.user_id=s.user_id and s
+.balance > 0;

  create view receipts as select * from unpaid_users;