/*
 * xmltables.sql -- Create or replace tables for storing XML in the db
 *
 *      Purpose: creates tables needed for XML database
 * 
 *      Created: 12 September 1999
 *       Author: Matt Jones
 * Organization: National Center for Ecological Analysis and Synthesis
 *      Version: '$Id: xmltables.sql 19 2000-04-11 17:57:28Z jones $'
 *
 */

/*
 * Drop all of the objects in proper order
 */
DROP SEQUENCE xml_attributes_id_seq;
DROP TRIGGER xml_attributes_before_insert;
DROP SEQUENCE xml_elements_id_seq;
DROP TRIGGER xml_elements_before_insert;
DROP TABLE xml_documents;
DROP TABLE xml_attributes;
DROP TABLE xml_elements;

/* 
 * Elements -- table to store XML Elements
 */
CREATE TABLE xml_elements (
	nodeid		NUMBER(20),
	parentnodeid	NUMBER(20),
	nodename	VARCHAR2(2000),
	nodedata	VARCHAR2(2000),
	date_created	DATE,
	date_updated	DATE,
   CONSTRAINT xml_elements_pk PRIMARY KEY (nodeid),
   CONSTRAINT xml_elements_parent_fk 
		FOREIGN KEY (parentnodeid) REFERENCES xml_elements
);

CREATE SEQUENCE xml_elements_id_seq;

CREATE TRIGGER xml_elements_before_insert
BEFORE INSERT ON xml_elements FOR EACH ROW
BEGIN
  SELECT xml_elements_id_seq.nextval
    INTO :new.nodeid
    FROM dual;
END;
/

/* 
 * Documents -- table to store XML document catalog
 */
CREATE TABLE xml_documents (
	docid		NUMBER(20),
	rootnodeid	NUMBER(20),
	docname		VARCHAR2(1000),
	doctype		VARCHAR2(1000),
	date_created	DATE,
	date_updated	DATE,
   CONSTRAINT xml_documents_pk PRIMARY KEY (docid),
   CONSTRAINT xml_documents_root_fk 
		FOREIGN KEY (rootnodeid) REFERENCES xml_elements
);

/* 
 * Attributes -- table to store XML Attributes
 */
CREATE TABLE xml_attributes (
	attributeid	NUMBER(20),
	nodeid		NUMBER(20),
	attributenumber	NUMBER(20),
	attributename	VARCHAR2(256),
	attributevalue	VARCHAR2(2000),
	date_created	DATE,
	date_updated	DATE,
   CONSTRAINT xml_attributes_pk PRIMARY KEY (attributeid),
   CONSTRAINT xml_attributes_parent_node FOREIGN KEY (nodeid) 
		REFERENCES xml_elements,
   CONSTRAINT xml_attributes_uniq_attribute UNIQUE (nodeid,attributename) 
);

CREATE SEQUENCE xml_attributes_id_seq;

CREATE TRIGGER xml_attributes_before_insert
BEFORE INSERT ON xml_attributes FOR EACH ROW
BEGIN
  SELECT xml_attributes_id_seq.nextval
    INTO :new.attributeid
    FROM dual;
END;
/