-- DDL to create the tables

create table d_node (
  node_name character varying(10) not null,
  parent_node character varying(10),
  constraint pk_node primary key (node_name),
  constraint fk_node foreign key (parent_node)
    references d_node (node_name)
    on update cascade on delete cascade
  );


-- **** Test update
insert into d_node (node_name, parent_node) values ('NodeA', null);
insert into d_node (node_name, parent_node) values ('NodeB', 'NodeA');
update d_node set parent_node='NodeB' where node_name='NodeA';

-- **** Test deletion with cascading deletions on deletes
delete from d_node;
insert into d_node (node_name, parent_node) values ('NodeA', 'NodeA');
insert into d_node (node_name, parent_node) values ('NodeB', 'NodeA');
delete from d_node where node_name='NodeA';