[Hibernate] Network Demo

[Boring, J. W, A. <jb...@at...>]

Could someone explain the objects and tables. I really don not =
understand the problem domain. How is vertex used here - math (The point =
at which the sides of an angle intersect), Astronomy (The highest point =
reached in the apparent motion of a celestial body), or Anatomy (The =
highest point of the skull)? None of these jive with "sink" or "source." =
Also, why does the edge table below need foreign keys to vertex?=20

Thanks much,

----------------------------------------------------------------- TABLES
create table vertex (
	creationDate DATE,=20
	name VARCHAR(50) not null unique,=20
	strength FLOAT,=20
	version_number INTEGER not null,=20
	vertex_id BIGINT not null,=20
	vertex_type VARCHAR(255) not null,=20
	primary key (vertex_id))
=09
create table edge (
	creationDate DATE,=20
	edge_cpcty FLOAT,=20
	edge_id BIGINT not null,=20
	edge_length FLOAT,=20
	name VARCHAR(50) not null unique,=20
	sink BIGINT not null,=20
	source BIGINT not null,=20
	primary key (edge_id))
=09
alter table edge add constraint=20
	edgeFK1 foreign key (sink) references vertex
=09
alter table edge add constraint=20
	edgeFK0 foreign key (source) references vertex
=09
create table hibernate_unique_key ( next_hi INTEGER )

insert into hibernate_unique_key values ( 0 )
-----------------------------------------------------------------=20

----------------------------------------------------------------- =
Classes
public class Edge {
	private float length;
	private String name;
	private float capacity;
	private Vertex source;
	private Vertex sink;
	private long key;
	private Date creationDate =3D new Date();
}
public class Vertex {
	private Set incoming =3D new HashSet();
	private Set outgoing =3D new HashSet();
	private String name;
	private long key;
	private int version;
	private Date creationDate =3D new Date();
}
public class Source extends Vertex {
	private float strength;
}
-----------------------------------------------------------------=20

Jeff Boring
Custom & Web Services Development
AT&T Labs
jb...@at...
(813) 878-3367