Primeiro veremos o script para criarmos o banco, criaremos duas tabelas:


-- Database: licitatorio_db

-- DROP DATABASE licitatorio_db;

CREATE DATABASE licitatorio_db
  WITH OWNER = postgres
       ENCODING = 'LATIN1'
       TABLESPACE = pg_default;


-- Table: nivel

-- DROP TABLE nivel;

CREATE TABLE nivel
(
  id_nivel serial NOT NULL,
  desc_nivel character varying NOT NULL,
  CONSTRAINT nivel_pkey PRIMARY KEY (id_nivel)
)
WITHOUT OIDS;
ALTER TABLE nivel OWNER TO postgres;
COMMENT ON TABLE nivel IS 'Nivel de acesso as funcoes do sistema';


-- Table: usuario

-- DROP TABLE usuario;

CREATE TABLE usuario
(
  id_usuario serial NOT NULL,
  nome_usuario character varying NOT NULL,
  login_usuario character varying NOT NULL,
  senha_usuario character varying NOT NULL,
  id_nivel integer NOT NULL,
  data_cadastro date NOT NULL DEFAULT now(),
  CONSTRAINT usuario_pkey PRIMARY KEY (id_usuario),
  CONSTRAINT usuario_fk FOREIGN KEY (id_nivel)
      REFERENCES nivel (id_nivel) MATCH SIMPLE
      ON UPDATE CASCADE ON DELETE NO ACTION
)
WITHOUT OIDS;
ALTER TABLE usuario OWNER TO postgres;
...