File Source for DatasetDb.php

<?php
// ----------------------------------------------------------------------------------
// Class: DatasetDb
// ----------------------------------------------------------------------------------
/**
* Persistent implementation of a Dataset in a database.
* A RDF dataset is a collection of named RDF graphs.
*
* @version $Id: fsource_dataset__datasetDatasetDb.php.html 310 2006-06-26 12:34:22Z tgauss $
* @author Daniel Westphal (http://www.d-westphal.de)
* @author Chris Bizer <chris@bizer.de>
*
* @package dataset
* @access public
***/
require_once(RDFAPI_INCLUDE_DIR.PACKAGE_DBASE);
class DatasetDb extends Dataset
{
/**
* Reference to databse connection.
*
* @var resource dbConnection
* @access private
*/
var $dbConnection;
/**
* Reference to the dbStore Object.
*
* @var $dbStore dbStore
* @access private
*/
var $dbStore;
/**
* Name of the Dataset
*
* @var string
* @access private
*/
var $setName;
/**
* Constructor
* You can supply a Dataset name.
*
* @param ADODBConnection
* @param DbStore
* @param string
* @access public
*/
function DatasetDb(&$dbConnection,&$dbStore,$datasetName)
{
$this->dbConnection=& $dbConnection;
$this->dbStore=&$dbStore;
$this->setName= $datasetName;
$this->_initialize();
}
/**
* Initialize
* Read all needed data into the set.
*
*
* @access private
*/
function _initialize()
{
$recordSet =& $this->dbConnection->execute("SELECT defaultModelUri
FROM datasets where datasetName='".$this->setName."'");
$this->defaultGraph=& $this->dbStore->getModel($recordSet->fields[0]);
}
// === Graph level methods ========================
/**
* Sets the Dataset name. Return true on success, false otherwise.
*
* @param string
* @access public
*/
function setDatasetName($datasetName)
{
if ($this->dbStore->datasetExists($datasetName))
return false;
$this->dbConnection->execute("UPDATE datasets SET datasetName='".$datasetName."'
where datasetName='".$this->setName."'");
$this->dbConnection->execute("UPDATE dataset_model SET datasetName='".$datasetName."'
where datasetName='".$this->setName."'");
$this->setName=$datasetName;
return true;
}
/**
* Returns the Datasets name.
*
* @return string
* @access public
*/
function getDatasetName()
{
return $this->setName;
}
/**
* Adds a NamedGraph to the set.
*
* @param NamedGraphDb
*/
function addNamedGraph(&$graph)
{
$graphNameURI=$graph->getGraphName();
$this->removeNamedGraph($graphNameURI);
$this->dbConnection->execute('INSERT INTO dataset_model VALUES("'.$this->setName.'",'.$graph->modelID.',"'.$graphNameURI.'")');
}
/**
* Overwrites the existting default graph.
*
* @param DbModel
*/
function setDefaultGraph(&$graph)
{
$this->dbConnection->execute('UPDATE datasets SET defaultModelUri ="'.$graph->modelURI.'" WHERE datasetName ="'.$this->setName.'"');
}
/**
* Returns a reference to the defaultGraph.
*
* @return NamedGraphDb
*/
function & getDefaultGraph()
{
$defaultGraphURI = $this->dbConnection->GetOne("SELECT defaultModelUri FROM datasets WHERE datasetName ='".$this->setName."'");
return ($this->dbStore->getNamedGraphDb($defaultGraphURI,'http://rdfapi-php/dataset_defaultGraph_'.$this->setName));
}
/**
* Returns true, if a defaultGraph exists. False otherwise.
*
* @return boolean
*/
function hasDefaultGraph()
{
return true;
}
/**
* Removes a NamedGraph from the set. Nothing happens
* if no graph with that name is contained in the set.
*
* @param string
*/
function removeNamedGraph($graphName)
{
$this->dbConnection->execute('DELETE FROM dataset_model WHERE datasetName="'.$this->setName.'" AND graphURI ="'.$graphName.'"');
}
/**
* Tells wether the Dataset contains a NamedGraph.
*
* @param string
* @return boolean
*/
function containsNamedGraph($graphName)
{
$count= $this->dbConnection->GetOne('SELECT count(*) FROM dataset_model WHERE datasetName="'.$this->setName.'" AND graphURI ="'.$graphName.'"');
return ($count>0);
}
/**
* Returns the NamedGraph with a specific name from the Dataset.
* Changes to the graph will be reflected in the set.
*
* @param string
* @return NamedGraphDb or null
*/
function &getNamedGraph($graphName)
{
if(!$this->containsNamedGraph($graphName))
return null;
$modelVars =& $this->dbConnection->execute("SELECT models.modelURI, models.modelID, models.baseURI
FROM models, dataset_model
WHERE dataset_model.graphURI ='" .$graphName ."' AND dataset_model.modelId= models.modelID");
return new NamedGraphDb($this->dbConnection, $modelVars->fields[0],
$modelVars->fields[1], $graphName ,$modelVars->fields[2]);
}
/**
* Returns the names of the namedGraphs in this set as strings in an array.
*
* @return Array
*/
function listGraphNames()
{
$recordSet =& $this->dbConnection->execute("SELECT graphURI FROM dataset_model WHERE datasetName ='".$this->setName."'");
$return=array();
while (!$recordSet->EOF)
{
$return[] = $recordSet->fields[0];
$recordSet->moveNext();
}
return $return;
}
/**
* Creates a new NamedGraph and adds it to the set. An existing graph with the same name will be replaced. But the old namedGraph remains in the database.
*
* @param string
* @param string
* @return NamedGraphDb
*/
function &createGraph($graphName,$baseURI = null)
{
$graph =& $this->dbStore->getNewNamedGraphDb(uniqid('http://rdfapi-php/namedGraph_'),$graphName,$baseURI);
$this->addNamedGraph(&$graph);
return $graph;
}
/**
* Deletes all NamedGraphs from the set.
*/
function clear()
{
$this->dbConnection->execute("DELETE FROM dataset_model WHERE datasetName ='".$this->setName."'");
}
/**
* Returns the number of NamedGraphs in the set. Empty graphs are counted.
*
* @return int
*/
function countGraphs()
{
return ($this->dbConnection->GetOne("SELECT count(*) FROM dataset_model WHERE datasetName ='".$this->setName."'"));
}
/**
* Returns an iterator over all {@link NamedGraph}s in the set.
*
* @return IteratorAllGraphsDb
*/
function &listNamedGraphs()
{
$recordSet =& $this->dbConnection->execute("SELECT graphURI FROM dataset_model WHERE datasetName ='".$this->setName."'");
return (new IteratorAllGraphsDb(&$recordSet,&$this));
}
/**
* Tells wether the set contains any NamedGraphs.
*
* @return boolean
*/
function isEmpty()
{
return ($this->countGraphs()==0);
}
/**
* Add all named graphs of the other dataset to this dataset.
*
* @param Dataset
*/
function addAll($otherDataset)
{
for($iterator = $otherDataset->listNamedGraphs(); $iterator->valid(); $iterator->next())
{
$this->addNamedGraph($iterator->current());
};
if ($otherDataset->hasDefaultGraph())
{
$this->defaultGraph = $this->defaultGraph->unite($otherDataset->getDefaultGraph());
}
}
// === Quad level methods ========================
/**
* Adds a quad to the Dataset. The argument must not contain any
* wildcards. If the quad is already present, nothing happens. A new
* named graph will automatically be created if necessary.
*
* @param Quad
*/
function addQuad(&$quad)
{
$graphName=$quad->getGraphName();
$graphName=$graphName->getLabel();
$graph=& $this->getNamedGraph($graphName);
if ($graph===null)
$graph=& $this->createGraph($graphName);
$statement=$quad->getStatement();
$graph->add($statement);
}
/**
* Tells wether the Dataset contains a quad or
* quads matching a pattern.
*
* @param Resource
* @param Resource
* @param Resource
* @param Resource
* @return boolean
*/
function containsQuad($graphName,$subject,$predicate,$object)
{
// static part of the sql statement
$sql = "SELECT count(*)
FROM statements, dataset_model
WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";
if($graphName!=null)
{
$sql.= " AND graphURI ='".$graphName->getLabel()."'";
}
// dynamic part of the sql statement
$sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);
return (($this->dbConnection->GetOne($sql))>0);
}
/**
* Deletes a Quad from the RDF dataset.
*
* @param Quad
*/
function removeQuad($quad)
{
$graphName=$quad->getGraphName();$graphName=$graphName->getLabel();
//find namedGraph IDs
$graphID = $this->dbConnection->GetOne("SELECT modelId FROM dataset_model WHERE graphURI ='$graphName'");
// static part of the sql statement
$sql = "DELETE FROM statements WHERE modelID = $graphID";
// dynamic part of the sql statement
$sql .= DbModel::_createDynSqlPart_SPO($quad->getSubject(), $quad->getPredicate(), $quad->getObject());
// execute the query
if($graphID)
$recordSet =& $this->dbConnection->execute($sql);
}
/**
* Counts the Quads in the RDF dataset. Identical Triples in
* different NamedGraphs are counted individually.
*
* @return int
*/
function countQuads()
{
$sql = "SELECT count(*)
FROM statements, dataset_model
WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";
return ((int)$this->dbConnection->GetOne($sql));
}
/**
* Finds Statements that match a quad pattern. The argument may contain
* wildcards.
*
* @param Resource or null
* @param Resource or null
* @param Resource or null
* @param Resource or null
* @return IteratorFindQuadsDb
*/
function &findInNamedGraphs($graphName,$subject,$predicate,$object,$returnAsTriples =false )
{
// static part of the sql statement
$sql = "SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is, dataset_model.graphURI
FROM statements, dataset_model
WHERE datasetName ='".$this->setName."' AND statements.modelID=dataset_model.modelId ";
if($graphName!=null)
{
$sql.= " AND graphURI ='".$graphName->getLabel()."'";
}
// dynamic part of the sql statement
$sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);
// execute the query
$recordSet =& $this->dbConnection->execute($sql);
return new IteratorFindQuadsDb(&$recordSet,&$this,$returnAsTriples);
}
/**
* Finds Statements that match a pattern in the default Graph. The argument may contain
* wildcards.
*
* @param Resource or null
* @param Resource or null
* @param Resource or null
* @return IteratorFindQuadsDb
*/
function &findInDefaultGraph($subject,$predicate,$object)
{
$defaultGraphID = (int)$this->dbConnection->GetOne("SELECT models.modelID FROM datasets, models WHERE datasets.datasetName ='".$this->setName."' AND datasets.defaultModelUri = models.modelURI");
// static part of the sql statement
$sql = "SELECT subject, predicate, object, l_language, l_datatype, subject_is, object_is
FROM statements
WHERE modelID ='$defaultGraphID'";
// dynamic part of the sql statement
$sql .= DbModel::_createDynSqlPart_SPO($subject, $predicate, $object);
// execute the query
$recordSet =& $this->dbConnection->execute($sql);
return new IteratorFindQuadsDb(&$recordSet,&$this,true);
}
}
?>

Source for file DatasetDb.php