/s3db3.5.10/pearlib/rdfapi-php/api/model/DbModel.php

<?php

require_once RDFAPI_INCLUDE_DIR . 'model/Model.php';

require_once RDFAPI_INCLUDE_DIR . 'model/Blanknode.php';

require_once RDFAPI_INCLUDE_DIR . 'model/Statement.php';



// ----------------------------------------------------------------------------------

// Class: DbModel

// ----------------------------------------------------------------------------------



/**

* This class provides methods for manipulating DbModels from DbStore.

* A DbModel is an RDF Model, which is persistently stored in a relational database.

* This Class uses the ADOdb Database Abstraction Library for PHP (http://adodb.sourceforge.net/).

*

*

* @version  $Id: DbModel.php,v 1.30 2007/05/29 16:51:52 cweiske Exp $

* @author   Radoslaw Oldakowski <radol@gmx.de>

*

* @package model

* @access	public

*/





class DbModel extends Model{



	/**

	* Database connection object.

	*

	* @var     object ADOConnection

	* @access	private

	*/

	var $dbConn;



	/**

	* Unique model URI.

	* Used to identify the DbModel.

	*

	* @var     string

	* @access	private

	*/

	var $modelURI;





	/**

	* Database internal modelID.

	* Used to avoid JOINs.

	*

	* @var     string

	* @access	private

	*/

	var $modelID;









	/**

	* Constructor

	* Do not call this directly.

	* Use the method getModel,getNewModel or putModel of the Class DbStore instead.

	*

	* @param   object ADOConnection  &$dbConnection

	* @param   string   $modelURI

	* @param   string   $modelID

	* @param   string   $baseURI

	* @access	public

	*/

	function DbModel(&$dbConnection, $modelURI, $modelID, $baseURI=NULL) {



		$this->dbConn =& $dbConnection;

		$this->modelURI = $modelURI;

		$this->modelID = $modelID;

		$this->baseURI = $this->_checkBaseURI($baseURI);

	}





	/**

	* Set a base URI for the DbModel.

	* Affects creating of new resources and serialization syntax.

	*

	* @param	string	$uri

	* @throws  SqlError

	* @access	public

	*/

	function setBaseURI($uri) {



		$this->baseURI = $this->_checkBaseURI($uri);



		$rs = $this->dbConn->execute("UPDATE models SET baseURI='" .$this->baseURI ."'

                                 WHERE modelID=" .$this->modelID);

		if (!$rs)

		$this->dbConn->errorMsg();

	}





	/**

	* Return the number of statements in this DbModel.

	*

	* @return	integer

	* @access	public

	*/

	function size() {



		$count =& $this->dbConn->getOne('SELECT COUNT(modelID) FROM statements

                                    WHERE modelID = ' .$this->modelID);

		return $count;

	}





	/**

	* Check if this DbModel is empty.

	*

	* @return	boolean

	* @access	public

	*/

	function isEmpty() {



		if ($this->size() == 0)

		return TRUE;

		return FALSE;

	}





	/**

	* Add a new triple to this DbModel.

	*

	* @param	object Statement	&$statement

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	* @return mixed   true on success, false if the statement is already in the model,

	*                 error message (string) on failure

	*/

	function add(&$statement) {



		if (!is_a($statement, 'Statement')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: add): Statement expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		if (!$this->contains($statement)) {



			$subject_is = $this->_getNodeFlag($statement->subject());

			$sql = "INSERT INTO statements

			        (modelID, subject, predicate, object, l_language, l_datatype, subject_is, object_is)

			        VALUES

                    (" .$this->modelID .","

			."'" .$statement->getLabelSubject() ."',"

			."'" .$statement->getLabelPredicate() ."',";



			if (is_a($statement->object(), 'Literal')) {

				$quotedLiteral = $this->dbConn->qstr($statement->obj->getLabel());

				$sql .=        $quotedLiteral .","

				."'" .$statement->obj->getLanguage() ."',"

				."'" .$statement->obj->getDatatype() ."',"

				."'" .$subject_is ."',"

				."'l')";

			}else{

				$object_is = $this->_getNodeFlag($statement->object());

				$sql .=   "'" .$statement->obj->getLabel() ."',"

				."'',"

				."'',"

				."'" .$subject_is ."',"

				."'" .$object_is ."')";

			}

			$rs =& $this->dbConn->execute($sql);

			if (!$rs) {

				return $this->dbConn->errorMsg();

            } else {

                return true;

            }

		} else {

			return false;

		}

	}





	/**

	* Alias for the method add().

	*

	* @param	object Statement	&$statement

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function addWithoutDuplicates(&$statement) {



		$this->add($statement);

	}





	/**

	* Remove the given triple from this DbModel.

	*

	* @param	object Statement	&$statement

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function remove(&$statement) {



		if (!is_a($statement, 'Statement')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: remove): Statement expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		$sql = 'DELETE FROM statements

           WHERE modelID=' .$this->modelID;

		$sql .= $this->_createDynSqlPart_SPO ($statement->subj, $statement->pred, $statement->obj);



		$rs =& $this->dbConn->execute($sql);

		if (!$rs)

		$this->dbConn->errorMsg();

	}





	/**

	* Short dump of the DbModel.

	*

	* @return	string

	* @access	public

	*/

	function toString() {



		return 'DbModel[modelURI=' .$this->modelURI .'; baseURI=' .$this->getBaseURI() .';  size=' .$this->size() .']';

	}





	/**

	* Dump of the DbModel including all triples.

	*

	* @return	string

	* @access	public

	*/

	function toStringIncludingTriples() {



		$memModel =& $this->getMemModel();

		return $memModel->toStringIncludingTriples();

	}







	/**

	* Create a MemModel containing all the triples of the current DbModel.

	*

	* @return object MemModel

	* @access public

	*/

	function & getMemModel() {



		$recordSet = $this->_getRecordSet($this);

		return $this->_convertRecordSetToMemModel($recordSet);

	}







    /**

    * Returns the model id

    *

    * @return int Model id number

    * @access public

    */

    function getModelID()

    {

        return $this->modelID;

    }







    /**

    * Returns the database connection object

    *

    * @return ADOdb Database object

    * @access public

    */

    function &getDbConn()

    {

        return $this->dbConn;

    }







	/**

	* Write the RDF serialization of the _DbModel as HTML.

	*

	* @access	public

	*/

	function writeAsHtml() {



		$memModel =& $this->getMemModel();

		$memModel->writeAsHtml();

	}





	/**

	* Write the RDF serialization of the DbModel as HTML table.

	*

	* @access	public

	*/

	function writeAsHtmlTable() {

		include_once(RDFAPI_INCLUDE_DIR.PACKAGE_UTILITY);

		$memModel =& $this->getMemModel();

		RDFUtil::writeHTMLTable($memModel);

	}





	/**

	* Write the RDF serialization of the DbModel to string.

	*

	* @return	string

	* @access	public

	*/

	function writeRdfToString() {



		$memModel =& $this->getMemModel();

		return $memModel->writeRdfToString();

	}





	/**

	* Saves the RDF,N3 or N-Triple serialization of the DbModel to a file.

	* You can decide to which format the model should be serialized by using a

	* corresponding suffix-string as $type parameter. If no $type parameter

	* is placed this method will serialize the model to XML/RDF format.

	* Returns FALSE if the DbModel couldn't be saved to the file.

	*

	* @access	public

	* @param 	string 	$filename

	* @param 	string 	$type

	* @throws   PhpError

	* @return	boolean

	*/

	function saveAs($filename, $type ='rdf') {



		$memModel = $this->getMemModel();

		$memModel->saveAs($filename, $type);



	}





	/**

	* Check if the DbModel contains the given statement.

	*

	* @param object Statement  &$statement

	* @return	boolean

	* @access	public

	*/

	function contains(&$statement) {



		$sql = 'SELECT modelID FROM statements

           WHERE modelID = ' .$this->modelID;

		$sql .= $this->_createDynSqlPart_SPO($statement->subj, $statement->pred, $statement->obj);



		$res =& $this->dbConn->getOne($sql);



		if (!$res)

		return FALSE;

		return TRUE;

	}





	/**

	* Determine if all of the statements in the given model are also contained in this DbModel.

	*

	* @param	object Model	&$model

	* @return	boolean

	* @access	public

	*/

	function containsAll(&$model) {



		if (is_a($model, 'MemModel')) {



			foreach($model->triples as $statement)

			if(!$this->contains($statement))

			return FALSE;

			return TRUE;

		}



		elseif (is_a($model, 'DbModel')) {



			$recordSet =& $this->_getRecordSet($model);

			while (!$recordSet->EOF) {

				if (!$this->_containsRow($recordSet->fields))

				return FALSE;

				$recordSet->moveNext();

			}

			return TRUE;

		}



		$errmsg = RDFAPI_ERROR . '(class: DbModel; method: containsAll): Model expected.';

		trigger_error($errmsg, E_USER_ERROR);

	}





	/**

	* Determine if any of the statements in the given model are also contained in this DbModel.

	*

	* @param	object Model	&$model

	* @return	boolean

	* @access	public

	*/

	function containsAny(&$model) {



		if (is_a($model, 'MemModel')) {



			foreach($model->triples as $statement)

			if($this->contains($statement))

			return TRUE;

			return FALSE;

		}



		elseif (is_a($model, 'DbModel')) {



			$recordSet =& $this->_getRecordSet($model);

			while (!$recordSet->EOF) {

				if ($this->_containsRow($recordSet->fields))

				return TRUE;

				$recordSet->moveNext();

			}

			return FALSE;

		}



		$errmsg = RDFAPI_ERROR . '(class: DbModel; method: containsAny): Model expected.';

		trigger_error($errmsg, E_USER_ERROR);

	}





	/**

	* General method to search for triples in the DbModel.

	* NULL input for any parameter will match anything.

	* Example:  $result = $m->find( NULL, NULL, $node );

	*           Finds all triples with $node as object.

	*

	* @param	object Resource	$subject

	* @param	object Resource	$predicate

	* @param	object Node	$object

	* @return	object MemModel

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function find($subject, $predicate, $object) {



		if ((!is_a($subject, 'Resource') && $subject != NULL) ||

		(!is_a($predicate, 'Resource') && $predicate != NULL) ||

		(!is_a($object, 'Node') && $object != NULL)) {



			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: find): Parameters must be subclasses of Node or NULL';

			trigger_error($errmsg, E_USER_ERROR);

		}



		// static part of the sql statement

		$sql = 'SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is

           FROM statements

           WHERE modelID = ' .$this->modelID;



		// dynamic part of the sql statement

		$sql .= $this->_createDynSqlPart_SPO($subject, $predicate, $object);



		// execute the query

		$recordSet =& $this->dbConn->execute($sql);



		if (!$recordSet)

		echo $this->dbConn->errorMsg();



		// write the recordSet into memory Model

		else

		return $this->_convertRecordSetToMemModel($recordSet);

	}





	/**

	* Method to search for triples using Perl-style regular expressions.

	* NULL input for any parameter will match anything.

	* Example:  $result = $m->find_regex( NULL, NULL, $regex );

	*           Finds all triples where the label of the object node matches

	*the regular expression.

	* Return an empty MemModel if nothing is found.

	* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

	* WARNING: Mhis method loads a DbModel into memory and performs the search

	*          on a MemModel, which can be slow with large models.

	* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

	*

	* @param	string	$subject_regex

	* @param	string	$predicate_regex

	* @param	string	$object_regex

	* @return	object MemModel

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function findRegex($subject_regex, $predicate_regex, $object_regex) {



		$mm =& $this->getMemModel();



		return $mm->findRegex($subject_regex, $predicate_regex, $object_regex);

	}





	/**

	* Return all tripels of a certain vocabulary.

	* $vocabulary is the namespace of the vocabulary inluding a # : / char at the end.

	* e.g. http://www.w3.org/2000/01/rdf-schema#

	* Return an empty model if nothing is found.

	*

	* @param	string	$vocabulary

	* @return	object MemModel

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function findVocabulary($vocabulary) {



		$sql = "SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is

           FROM statements

           WHERE modelID = " .$this->modelID ."

           AND predicate LIKE '" .$vocabulary ."%'";



		$recordSet =& $this->dbConn->execute($sql);



		if (!$recordSet)

		echo $this->dbConn->errorMsg();



		// write the recordSet into memory Model

		else

		return $this->_convertRecordSetToMemModel($recordSet);

	}





	/**

	* Search for triples and return the first matching statement.

	* NULL input for any parameter will match anything.

	* Return an NULL if nothing is found.

	* You can set an search offset with $offset.

	*

	* @param	object Resource	$subject

	* @param	object Resource	$predicate

	* @param	object Node	$object

	* @param	integer	$offset

	* @return	object Statement

	* @throws  PhpError

	* @throws  SqlError

	* @access	public

	*/

	function findFirstMatchingStatement($subject, $predicate, $object, $offset = -1) {



		if ((!is_a($subject, 'Resource') && $subject != NULL) ||

		(!is_a($predicate, 'Resource') && $predicate != NULL) ||

		(!is_a($object, 'Node') && $object != NULL)) {



			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: find): Parameters must be subclasses of Node or NULL';

			trigger_error($errmsg, E_USER_ERROR);

		}



		// static part of the sql statement

		$sql = 'SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is

           FROM statements

           WHERE modelID = ' .$this->modelID;



		// dynamic part of the sql statement

		$sql .= $this->_createDynSqlPart_SPO($subject, $predicate, $object);



		// execute the query

		$recordSet =& $this->dbConn->selectLimit($sql,1,($offset));



		if (!$recordSet)

		echo $this->dbConn->errorMsg();

		else {

			if (!$recordSet->fields)

			return NULL;

			else {

				$memModel = $this->_convertRecordSetToMemModel($recordSet);

				return $memModel->triples[0];

			}

		}

	}





	/**

	* Search for triples and return the number of matches.

	* NULL input for any parameter will match anything.

	*

	* @param	object Resource	$subject

	* @param	object Resource	$predicate

	* @param	object Node  	$object

	* @return	integer

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function findCount($subject, $predicate, $object) {



		if ((!is_a($subject, 'Resource') && $subject != NULL) ||

		(!is_a($predicate, 'Resource') && $predicate != NULL) ||

		(!is_a($object, 'Node') && $object != NULL)) {



			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: find): Parameters must be subclasses of Node or NULL';

			trigger_error($errmsg, E_USER_ERROR);

		}



		// static part of the sql statement

		$sql = 'SELECT COUNT(*)

           FROM statements

           WHERE modelID = ' .$this->modelID;



		// dynamic part of the sql statement

		$sql .= $this->_createDynSqlPart_SPO($subject, $predicate, $object);



		// execute the query

		$recordSet =& $this->dbConn->execute($sql);



		if (!$recordSet)

		echo $this->dbConn->errorMsg();

		else

		return $recordSet->fields[0];

	}





	/**

	* Perform an RDQL query on this DbModel.

	* This method returns an associative array of variable bindings.

	* The values of the query variables can either be RAP's objects (instances of Node)

	* if $returnNodes set to TRUE, or their string serialization.

	*

	* @access	public

	* @param string $queryString

	* @param boolean $returnNodes

	* @return  array   [][?VARNAME] = object Node  (if $returnNodes = TRUE)

	*      OR  array   [][?VARNAME] = string

	*

	*/

	function rdqlQuery($queryString, $returnNodes = TRUE) {

		require_once(RDFAPI_INCLUDE_DIR.PACKAGE_RDQL);

		$parser = new RdqlParser();

		$parsedQuery =& $parser->parseQuery($queryString);



		// this method can only query this DbModel

		// if another model was specified in the from clause throw an error

		if (isset($parsedQuery['sources'][0]))

		if($parsedQuery['sources'][0] != $this->modelURI) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: rdqlQuery):';

			$errmsg .= ' this method can only query this DbModel';

			trigger_error($errmsg, E_USER_ERROR);

		}



		$engine = new RdqlDbEngine();

		$res =& $engine->queryModel($this, $parsedQuery, $returnNodes);



		return $res;

	}





	/**

	* Perform an RDQL query on this DBModel.

	* This method returns an RdqlResultIterator of variable bindings.

	* The values of the query variables can either be RAP's objects (instances of Node)

	* if $returnNodes set to TRUE, or their string serialization.

	*

	* @access	public

	* @param string $queryString

	* @param boolean $returnNodes

	* @return  object RdqlResultIterator = with values as object Node  (if $returnNodes = TRUE)

	*      OR  object RdqlResultIterator = with values as strings if (if $returnNodes = FALSE)

	*

	*/

	function rdqlQueryAsIterator($queryString, $returnNodes = TRUE) {

		require_once(RDFAPI_INCLUDE_DIR.PACKAGE_RDQL);

		return new RdqlResultIterator($this->rdqlQuery($queryString, $returnNodes));

	}



	/**

	* General method to replace nodes of a DbModel.

	* NULL input for any parameter will match nothing.

	* Example:  $m->replace($resource, NULL, $node, $replacement);

	*           Replaces all $node objects beeing subject or object in

	*           any triple of the model with the $replacement node.

	* Throw an error in case of a paramter mismatch.

	*

	* @param	object Resource	$subject

	* @param	object Resource	$predicate

	* @param	object Node	$object

	* @param	object Node	$replacement

	* @throws	PhpError

	* @throws  SqlError

	* @access	public

	*/

	function replace($subject, $predicate, $object, $replacement) {



		// check the correctness of the passed parameters

		if ( ((!is_a($subject, 'Resource') && $subject != NULL) ||

		(!is_a($predicate, 'Resource') && $predicate != NULL) ||

		(!is_a($object, 'Node') && $object != NULL)) ||

		(($subject != NULL && is_a($replacement, 'Literal')) ||

		($predicate != NULL && (is_a($replacement, 'Literal') ||

		is_a($replacement, 'BlankNode')))) )

		{

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: find): Parameter mismatch';

			trigger_error($errmsg, E_USER_ERROR);

		}



		if (!(!$subject && !$predicate && !$object)) {



			// create an update sql statement

			$comma = '';

			$sql = 'UPDATE statements

             SET ';

			if ($subject) {

				$sql .= " subject ='" .$replacement->getLabel() ."', "

				." subject_is='" .$this->_getNodeFlag($replacement) ."' ";

				$comma = ',';

			}

			if ($predicate) {

				$sql .= $comma ." predicate='" .$replacement->getLabel() ."' ";

				$comma = ',';

			}

			if ($object) {

				$quotedObject = $this->dbConn->qstr($replacement->getLabel());

				$sql .= $comma .' object=' .$quotedObject

				.", object_is='" .$this->_getNodeFlag($replacement) ."' ";

				if (is_a($replacement, 'Literal')) {

					$sql .= ", l_language='" .$replacement->getLanguage() ."' "

					.", l_datatype='" .$replacement->getDataType() ."' ";

				}

			}

			$sql .= 'WHERE modelID = ' .$this->modelID;

			$sql .= $this->_createDynSqlPart_SPO($subject, $predicate, $object);



			// execute the query

			$rs =& $this->dbConn->execute($sql);



			if (!$rs)

			echo $this->dbConn->errorMsg();

		}

	}





	/**

	* Check if two models are equal.

	* Two models are equal if and only if the two RDF graphs they represent are isomorphic.

	*

	* Warning: This method doesn't work correct with models where the same blank node has different

	* identifiers in the two models. We will correct this in a future version.

	*

	* @param	object	model &$that

	* @return	boolean

	* @throws  PhpError

	* @access	public

	*/



	function equals(&$that)  {



		if (!is_a($that, 'Model')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: equals): Model expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		if ($this->size() != $that->size())

		return FALSE;



		include_once(RDFAPI_INCLUDE_DIR. "util/ModelComparator.php");

		return ModelComparator::compare($this,$that);

	}





	/**

	* Return a new MemModel that is the set-union the model with another model.

	*

	* The result of taking the set-union of two or more RDF graphs (i.e. sets of triples)

	* is another graph, which we will call the merge of the graphs.

	* Each of the original graphs is a subgraph of the merged graph. Notice that when forming

	* a merged graph, two occurrences of a given uriref or literal as nodes in two different

	* graphs become a single node in the union graph (since by definition they are the same

	* uriref or literal) but blank nodes are not 'merged' in this way; and arcs are of course

	* never merged. In particular, this means that every blank node in a merged graph can be

	* identified as coming from one particular graph in the original set of graphs.

	*

	* Notice that one does not, in general, obtain the merge of a set of graphs by concatenating

	* their corresponding N-triples documents and constructing the graph described by the merged

	* document, since if some of the documents use the same node identifiers, the merged document

	* will describe a graph in which some of the blank nodes have been 'accidentally' merged.

	* To merge Ntriples documents it is necessary to check if the same nodeID is used in two or

	* more documents, and to replace it with a distinct nodeID in each of them, before merging the

	* documents. (Not implemented yet !!!!!!!!!!!)

	*

	* @param	object Model	$model

	* @return	object MemModel

	* @throws PhpError

	* @access	public

	*

	*/

	function & unite(&$model)  {



		if (!is_a($model, 'Model')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: unite): Model expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		if (is_a($model, 'MemModel')) {



			$thisModel =& $this->getMemModel();

			return $thisModel->unite($model);

		}



		elseif (is_a($model, 'DbModel')) {



			$thisModel =& $this->getMemModel();

			$thatModel =& $model->getMemModel();

			return $thisModel->unite($thatModel);

		}

	}





	/**

	* Return a new MemModel that is the subtraction of another model from this DbModel.

	*

	* @param	object Model	$model

	* @return	object MemModel

	* @throws PhpError

	* @access	public

	*/



	function & subtract(&$model)  {



		if (!is_a($model, 'Model')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: subtract): Model expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		if (is_a($model, 'MemModel')) {



			$thisModel =& $this->getMemModel();

			return $thisModel->subtract($model);

		}



		elseif (is_a($model, 'DbModel')) {



			$thisModel =& $this->getMemModel();

			$thatModel =& $model->getMemModel();

			return $thisModel->subtract($thatModel);

		}

	}





	/**

	* Return a new MemModel containing all the statements which are in both

	* this model and the given model.

	*

	* @param	object Model	$model

	* @return	object MemModel

	* @throws  PhpError

	* @access	public

	*/

	function & intersect(&$model)  {



		if (is_a($model, 'MemModel')) {



			$thisModel =& $this->getMemModel();

			return $thisModel->intersect($model);

		}



		elseif (is_a($model, 'DbModel')) {



			$thisModel =& $this->getMemModel();

			$thatModel =& $model->getMemModel();

			return $thisModel->intersect($thatModel);

		}



		$errmsg = RDFAPI_ERROR . '(class: DbModel; method: intersect: Model expected.';

		trigger_error($errmsg, E_USER_ERROR);

	}





	/**

	* Add the given model to this DbModel.

	* This function monitors for SQL errors, and will commit if no errors have occured,

	* otherwise it will rollback.

	* If any statement of the model to be added to this model contains a blankNode

	* with an identifier already existing in this model, a new blankNode is generated.

	*

	* @param	object Model	$model

	* @throws  PhpError

	* @access	public

	*/

	function addModel(&$model)  {



		if (!is_a($model, 'Model')) {

			$errmsg = RDFAPI_ERROR . '(class: DbModel; method: addModel): Model expected.';

			trigger_error($errmsg, E_USER_ERROR);

		}



		$blankNodes_tmp = array();



		if (is_a($model, 'MemModel')) {



			$this->dbConn->startTrans();

			foreach ($model->triples as $statement)

			$this->_addStatementFromAnotherModel($statement, $blankNodes_tmp);

			$this->addParsedNamespaces($model->getParsedNamespaces());



			$this->dbConn->completeTrans();

		}



		elseif (is_a($model, 'DbModel')) {



			$this->dbConn->startTrans();

			$memModel =& $model->getMemModel();

			foreach($memModel->triples as $statement)

			$this->_addStatementFromAnotherModel($statement, $blankNodes_tmp);

			$this->addParsedNamespaces($model->getParsedNamespaces());

			$this->dbConn->completeTrans();

		}

	}





	/**

	* Reify the DbModel.

	* Return a new MemModel that contains the reifications of all statements of this DbModel.

	*

	* @return	object	MemModel

	* @access	public

	*/

	function & reify() {



		$memModel =& $this->getMemModel();

		return $memModel->reify();

	}



	/**

	* Remove this DbModel from database and clean up.

	* This function monitors for SQL errors, and will commit if no errors have occured,

	* otherwise it will rollback.

	*

	* @throws  SqlError

	* @access	public

	*/

	function delete() {



		$this->dbConn->startTrans();

		$this->dbConn->execute('DELETE FROM models

                                  WHERE modelID=' .$this->modelID);

		$this->dbConn->execute('DELETE FROM statements

                                  WHERE modelID=' .$this->modelID);



		if (!$this->dbConn->completeTrans())

		echo $this->dbConn->errorMsg();

		else

		$this->close();

	}





	/**

	* Close this DbModel

	*

	* @access	public

	*/

	function close() {



		unset($this);

	}





	// =============================================================================

	// **************************** private methods ********************************

	// =============================================================================











	/**

	* If the URI doesn't end with # : or /, then a # is added to the URI.

	* Used at setting the baseURI of this DbModel.

	*

	* @param   string  $uri

	* @return  string

	* @access	private

	*/

	function _checkBaseURI($uri)  {



		if ($uri != NULL) {

			$c = substr($uri, strlen($uri)-1 ,1);

			if (!($c=='#' || $c==':' || $c=='/' || $c=="\\"))

			$uri .= '#';

		}

		return $uri;

	}





	/**'

	* Return the flag of the Node object.

	* r - Resource, b - BlankNode, l - Literal

	*

	* @param   object Node $object

	* @return  string

	* @access	private

	*/

	function _getNodeFlag($object)  {



		return is_a($object,'BlankNode')?'b':(is_a($object,'Resource')?'r':'l');

	}





	/**

	* Convert an ADORecordSet to a memory Model.

	*

	* Every successful database query returns an ADORecordSet object which is actually

	* a cursor that holds the current row in the array fields[].

	* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

	* !!! This method can only be applied to a RecordSet with array fields[]

	* !!! containing a representation of the database table: statements,

	* !!! with an index corresponding to following table columns:

	* !!! [0] - subject, [1] - predicate, [2] - object, [3] - l_language,

	* !!! [4] - l_datatype, [5] - subject_is, [6] - object_is

	* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

	*

	* @param   object  ADORecordSet

	* @return  object  MemModel

	* @access	private

	*/

	function _convertRecordSetToMemModel(&$recordSet)  {



		$res = new MemModel($this->baseURI);

		while (!$recordSet->EOF) {



			// subject

			if ($recordSet->fields[5] == 'r')

			$sub = new Resource($recordSet->fields[0]);

			else

			$sub = new BlankNode($recordSet->fields[0]);



			// predicate

			$pred = new Resource($recordSet->fields[1]);



			// object

			if ($recordSet->fields[6] == 'r')

			$obj = new Resource($recordSet->fields[2]);

			elseif ($recordSet->fields[6] == 'b')

			$obj = new BlankNode($recordSet->fields[2]);

			else {

				$obj = new Literal($recordSet->fields[2], $recordSet->fields[3]);

				if ($recordSet->fields[4])

				$obj->setDatatype($recordSet->fields[4]);

			}



			$statement = new Statement($sub, $pred, $obj);

			$res->add($statement);



			$recordSet->moveNext();

		}

		$res->addParsedNamespaces($this->getParsedNamespaces());

		return $res;

	}





	/**

	* Create the dynamic part of an sql statement selecting triples with the

	* given parameters ($subject, $predicate, $object).

	*

	* @param	object Resource	$subject

	* @param	object Resource	$predicate

	* @param	object Node	$object

	* @return  string

	* @access	private

	*/

	function _createDynSqlPart_SPO($subject, $predicate, $object) {



		// conditions derived from the parameters passed to the function



		$subject_is=is_a($subject,'BlankNode')?'b':(is_a($subject,'Resource')?'r':'l');

		$sql='';

		if ($subject != NULL)

		$sql .= " AND subject='" .$subject->getLabel() ."'

                AND subject_is='" .$subject_is ."'";

		if ($predicate != NULL)

		$sql .= " AND predicate='" .$predicate->getLabel() ."'";

		if ($object != NULL) {

			$object_is = is_a($object,'BlankNode')?'b':(is_a($object,'Resource')?'r':'l');

			if (is_a($object, 'Resource'))

			$sql .= " AND object='" .$object->getLabel() ."'

                   AND object_is ='" .$object_is ."'";

			else  {

				$quotedLiteral = $this->dbConn->qstr($object->getLabel());

				$sql .= " AND object=" .$quotedLiteral ."

                   AND l_language='" .$object->getLanguage() ."'

                   AND l_datatype='" .$object->getDataType() ."'

                   AND object_is ='" .$object_is ."'";

			}

		}

		return $sql;

	}





	/**

	* Get an ADORecordSet with array fields[] containing a representation of

	* the given DbModel stored in the table: statements, with an index corresponding

	* to following table columns:

	* [0] - subject, [1] - predicate, [2] - object, [3] - l_language,

	* [4] - l_datatype, [5] - subject_is, [6] - object_is

	* (This method operates on data from a DbModel without loading it into a memory model

	*  in order to save resources and improve speed).

	*

	* @param	object DbModel	$DbModel

	* @return  object ADORecordSet

	* @access	private

	*/

	function _getRecordSet (&$dbModel) {



		$sql = 'SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is

           FROM statements

           WHERE modelID = ' .$dbModel->modelID;



		return $recordSet =& $this->dbConn->execute($sql);

	}





	/**

	* Check if this DbModel contains the given row from the array fields[] of an ADORecordSet

	* The array index corresponds to following table columns:

	* [0] - subject, [1] - predicate, [2] - object, [3] - l_language,

	* [4] - l_datatype, [5] - subject_is, [6] - object_is

	*

	* @param   array  $row

	* @return  boolean

	* @access	private

	*/

	function _containsRow ($row) {



		$quotedObject = $this->dbConn->qstr($row[2]);

		$sql = "SELECT modelID FROM statements

           WHERE modelID = " .$this->modelID ."

           AND subject ='" .$row[0] ."'

           AND predicate ='" .$row[1] ."'

           AND object =" .$quotedObject ."

           AND l_language='" .$row[3] ."'

           AND l_datatype='" .$row[4] ."'

           AND subject_is='" .$row[5] ."'

           AND object_is='" .$row[6] ."'";



		$res =& $this->dbConn->getOne($sql);



		if (!$res)

		return FALSE;

		return TRUE;

	}











	/**

	* Returns the models namespaces.

	*

	* @author   Tobias Gau?<tobias.gauss@web.de>

	* @access   public

	* @return   Array

	*/

	function getParsedNamespaces(){

		$sql = "SELECT * FROM namespaces

           WHERE modelID = " .$this->modelID;

		$temp=false;

		$res = $this->dbConn->execute($sql);

		if($res){

			while (!$res->EOF) {

				$temp[$res->fields[1]]=$res->fields[2];

				$res->moveNext();

			}

		}

		return $temp;

	}







	/**

	* Adds the namespaces to the model. This method is called by

	* the parser. !!!! addParsedNamespaces() not overwrites manual

	* added namespaces in the model !!!!

	*

	* @author   Tobias Gau?<tobias.gauss@web.de>

	* @access   public

	* @param    Array $newNs

	*/

	function addParsedNamespaces($newNs){

		if($newNs)

		foreach($newNs as $namespace => $prefix){

			$this->addNamespace($prefix, $namespace);

		}

	}





	/**

	* Adds a namespace and prefix to the model.

	*

	* @author   Tobias Gau?<tobias.gauss@web.de>

	* @access   public

	* @param    String $prefix, String $nmsp

	*/

	function addNamespace($prefix,$nmsp){



		if($nmsp != '' && $prefix !=''){

			if($this->_checkNamespace($nmsp)){

				$sql = "UPDATE namespaces SET prefix='".$prefix."' WHERE

				modelID=".$this->modelID." AND namespace='".$nmsp."'";

			}else{

				$sql = "INSERT INTO namespaces

                    (modelID, namespace, prefix)

                    VALUES

                    (" .$this->modelID .","

				."'" .$nmsp ."',"

				."'" .$prefix."')";

			}



			$rs =& $this->dbConn->execute($sql);

			if (!$rs)

			$this->dbConn->errorMsg();

		}

	}



	/**

	* checks if a namespace is already in the model.

	*

	* @author   Tobias Gau?<tobias.gauss@web.de>

	* @access   private

	* @param    Array $newNs

	*/

	function _checkNamespace($nmsp){

		$res = true;

		$sql = "SELECT * FROM namespaces

          	 WHERE modelID = " .$this->modelID." AND

			namespace='".$nmsp."'" ;

		$rs =& $this->dbConn->execute($sql);

		if (!$rs){

			$this->dbConn->errorMsg();

		}else{

			if($rs->fields == false)

			$res = false;

		}

		return $res;





	}



	/**

	* Returns a FindIterator for traversing the MemModel.

	* @access	public

	* @return	object	FindIterator

	*/

	function & iterFind($sub=null,$pred=null,$obj=null) {

		// Import Package Utility

		include_once(RDFAPI_INCLUDE_DIR.PACKAGE_UTILITY);



		$if = new IterFind($this,$sub,$pred,$obj);

		return $if;

	}



	/**

	* removes a single namespace from the model

	*

	* @author   Tobias Gau?<tobias.gauss@web.de>

	* @access   public

	* @param    String $nmsp

	*/

	function removeNamespace($nmsp){



		$sql = 'DELETE FROM namespaces

           WHERE modelID=' .$this->modelID." AND namespace='".$nmsp."'";



		$rs =& $this->dbConn->execute($sql);

		if (!$rs)

		$this->dbConn->errorMsg();

	}









	/**

	* Add the given row from the array fields[] of an ADORecordSet to this DbModel

	* The array index corresponds to following table columns:

	* [0] - subject, [1] - predicate, [2] - object, [3] - l_language,

	* [4] - l_datatype, [5] - subject_is, [6] - object_is

	*

	* @param   array  $row

	* @throws  SqlError

	* @access	private

	*

	function _insertRow ($row) {



	$quotedObject = $this->dbConn->qstr($row[2]);

	$sql = "INSERT INTO statements VALUES

	(" .$this->modelID .","

	."'" .$row[0] ."',"

	."'" .$row[1] ."',"

	.""  .$quotedObject .","

	."'" .$row[3] ."',"

	."'" .$row[4] ."',"

	."'" .$row[5] ."',"

	."'" .$row[6] ."')";



	$rs =& $this->dbConn->execute($sql);

	if (!$rs)

	$this->dbConn->errorMsg();

	}

	*/



} // end: Class DbModel

?>