/**
* Adds a graph pattern to the result part.
*
* @param Erfurt_Sparql_GraphPattern $pattern
*/
public function addGraphPattern($pattern)
{
$pattern->setId($this->graphPatternCounter++);
$this->resultPart[] = $pattern;
}
/**
* Creates some SQL statements from the given triple pattern
* array.
*
* @param QueryTriple $triple Array containing subject, predicate and object
* @param GraphPattern $graphPattern Graph pattern object
*
* @return array Array consisting of on array and two string values:
* SELECT, FROM and WHERE part
*/
function getTripleSql(Erfurt_Sparql_QueryTriple $triple, Erfurt_Sparql_GraphPattern $graphPattern, $arResultVars)
{
$arSelect = array();
$strFrom = null;
$strWhere = null;
$strWhereEquality = '';
$bWhereEqualitySubject = false;
$bWhereEqualityPredicate = false;
$bWhereEqualityObject = false;
$subject = $triple->getSubject();
$predicate = $triple->getPredicate();
$object = $triple->getObject();
$arRefVars = array();
$strTablePrefix = 't' . $this->nTableId;
/**
* SELECT part
* We do select only the columns we need for variables
*/
require_once 'Erfurt/Sparql/Variable.php';
if (Erfurt_Sparql_Variable::isVariable($subject)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$subject])) {
//already selected -> add equality check
$bWhereEqualitySubject = true;
$this->arUsedVarTypes[$subject]['s'] = true;
} else {
#if (isset($this->arVarAssignments[$subject][0])) {
# $strTablePrefix = $this->arVarAssignments[$subject][0];
#}
if (!isset($this->arVarAssignments[$subject])) {
$this->arVarAssignments[$subject] = array($strTablePrefix, 's');
}
#$this->arVarAssignments[$subject] = array($strTablePrefix, 's');
$this->arVarAssignments[$subject][1] = 's';
$this->arUnionVarAssignments[$this->nUnionCount][$subject] = array($strTablePrefix, 's');
$this->arUsedVarTypes[$subject]['s'] = true;
if ($this->isResultVar($subject, $arResultVars)) {
//new variable that needs to be selected
$arSelect[$subject] = $this->createVariableSelectArray('s', $subject, $strTablePrefix);
if (isset($this->arUsedVarAssignments[$subject])) {
$arRefVars[$subject] = $strTablePrefix . '.s';
} else {
$this->arUsedVarAssignments[$subject] = $strTablePrefix . '.s';
}
}
}
} else {
if (strlen($subject) > 160) {
$subject = substr((string) $subject, 0, 128) . md5((string) $subject);
}
}
if (Erfurt_Sparql_Variable::isVariable($predicate)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$predicate])) {
//already selected -> add equality check
$bWhereEqualityPredicate = true;
$this->arUsedVarTypes[$predicate]['p'] = true;
} else {
#if (isset($this->arVarAssignments[$predicate][0])) {
# $strTablePrefix = $this->arVarAssignments[$predicate][0];
#}
if (!isset($this->arVarAssignments[$predicate])) {
$this->arVarAssignments[$predicate] = array($strTablePrefix, 'p');
}
#$this->arVarAssignments[$predicate] = array($strTablePrefix, 'p');
$this->arVarAssignments[$predicate][1] = 'p';
$this->arUnionVarAssignments[$this->nUnionCount][$predicate] = array($strTablePrefix, 'p');
$this->arUsedVarTypes[$predicate]['p'] = true;
if ($this->isResultVar($predicate, $arResultVars)) {
$arSelect[$predicate] = $this->createVariableSelectArray('p', $predicate, $strTablePrefix);
if (isset($this->arUsedVarAssignments[$predicate])) {
$arRefVars[$predicate] = $strTablePrefix . '.p';
} else {
$this->arUsedVarAssignments[$predicate] = $strTablePrefix . '.p';
}
}
}
} else {
if (strlen($predicate) > 160) {
$predicate = substr((string) $predicate, 0, 128) . md5((string) $predicate);
}
}
if (Erfurt_Sparql_Variable::isVariable($object)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$object])) {
//already selected -> add equality check
$bWhereEqualityObject = true;
$this->arUsedVarTypes[$object]['o'] = true;
} else {
#if (isset($this->arVarAssignments[$object][0])) {
# $strTablePrefix = $this->arVarAssignments[$object][0];
#}
if (!isset($this->arVarAssignments[$object])) {
$this->arVarAssignments[$object] = array($strTablePrefix, 'o');
}
$this->arVarAssignments[$object][1] = 'o';
$this->arUnionVarAssignments[$this->nUnionCount][$object] = array($strTablePrefix, 'o');
$this->arUsedVarTypes[$object]['o'] = true;
if ($this->isResultVar($object, $arResultVars)) {
$arSelect[$object] = $this->createVariableSelectArray('o', $object, $strTablePrefix);
if (isset($this->arUsedVarAssignments[$object])) {
$arRefVars[$object] = $strTablePrefix . '.o';
} else {
$this->arUsedVarAssignments[$object] = $strTablePrefix . '.o';
}
}
if (isset($this->query->varLanguages[$object]) && $this->query->varLanguages[$object] !== null) {
$strWhereEquality .= ' AND ' . $strTablePrefix . '.ol="' . addslashes($this->query->varLanguages[$object]) . '"';
}
if (isset($this->query->varDatatypes[$object]) && $this->query->varDatatypes[$object] !== null) {
$strWhereEquality .= ' AND ' . $strTablePrefix . '.ol="' . addslashes($this->query->varDatatypes[$object]) . '"';
}
}
} else {
if (strlen($object) > 160) {
$object = substr((string) $object, 0, 128) . md5((string) $object);
}
}
/**
* WhereEquality - needs to be done now because strTablePrefix may change
*/
if ($bWhereEqualitySubject) {
$strWhereEquality .= ' AND ' . $this->getSqlEqualityCondition(array($strTablePrefix, 's'), $this->arVarAssignments[$subject]);
}
if ($bWhereEqualityPredicate) {
$strWhereEquality .= ' AND ' . $this->getSqlEqualityCondition(array($strTablePrefix, 'p'), $this->arVarAssignments[$predicate]);
}
if ($bWhereEqualityObject) {
$strWhereEquality .= ' AND ' . $this->getSqlEqualityCondition(array($strTablePrefix, 'o'), $this->arVarAssignments[$object]);
}
/**
* FROM part
*/
//receive tableName from QueryCache ; if QueryCache dont have some special views
//the original tableName will be chosen
$tableName = $this->tblStatements;
if ($viewName = Erfurt_App::getInstance()->getQueryCache()->getMaterializedViewName($subject, $predicate, $object)) {
$tableName = $viewName;
}
if ($this->nUnionTriplePatternCount == 0) {
//first FROM
$strFrom = $tableName . ' as ' . $strTablePrefix;
} else {
//normal join
if (count($this->arModelIds) == 1) {
$strFrom = 'LEFT JOIN ' . $tableName . ' as ' . $strTablePrefix . ' ON t0.g=' . $strTablePrefix . '.g';
} else {
if (count($this->arModelIds) > 1) {
$arIDs = array();
foreach ($this->arModelIds as $nId) {
$arIDs[] = $strTablePrefix . '.g=' . intval($nId);
}
$strFrom = 'LEFT JOIN ' . $tableName . ' as ' . $strTablePrefix . ' ON (' . implode(' OR ', $arIDs) . ')';
} else {
$strFrom = 'LEFT JOIN ' . $tableName . ' as ' . $strTablePrefix . ' ON t0.g=' . $strTablePrefix . '.g';
}
}
if ($graphPattern->getOptional() !== null) {
$strFrom .= $this->getSqlCondition($subject, $strTablePrefix, 's') . $this->getSqlCondition($predicate, $strTablePrefix, 'p') . $this->getSqlCondition($object, $strTablePrefix, 'o') . $strWhereEquality;
}
}
/**
* WHERE part
*/
if ($this->nUnionTriplePatternCount == 0) {
if (count($this->arModelIds) == 1) {
$strWhere = $strTablePrefix . '.g=' . intval(reset($this->arModelIds));
} else {
if (count($this->arModelIds) > 1) {
$arIDs = array();
foreach ($this->arModelIds as $nId) {
$arIDs[] = $strTablePrefix . '.g=' . intval($nId);
}
$strWhere = '(' . implode(' OR ', $arIDs) . ')';
} else {
//so that we can append an AND
$strWhere = '1';
}
}
}
if ($graphPattern->getOptional() === null || $this->nGraphPatternCount == 0) {
$strWhere .= $this->getSqlCondition($subject, $strTablePrefix, 's') . $this->getSqlCondition($predicate, $strTablePrefix, 'p') . $this->getSqlCondition($object, $strTablePrefix, 'o') . $strWhereEquality;
}
return array($arSelect, $strFrom, $strWhere);
}
/**
* Constructs a result graph.
*
* @param array $arVartable A table containing the result vars and their bindings.
* @param Erfurt_Sparql_GraphPattern $constructPattern The CONSTRUCT pattern.
* @return array
*/
protected function _constructGraph($arVartable, $constructPattern)
{
$resultGraph = array();
if (!$arVartable) {
return $resultGraph;
}
$tp = $constructPattern->getTriplePatterns();
$bnode = 0;
foreach ($arVartable as $value) {
foreach ($tp as $triple) {
$subVar = substr($triple->getSubject(), 1);
$predVar = substr($triple->getPredicate(), 1);
$objVar = substr($triple->getObject(), 1);
$sub = $value["{$subVar}"]['value'];
$pred = $value["{$predVar}"]['value'];
$obj = $value["{$objVar}"];
if (!isset($resultGraph["{$sub}"])) {
$resultGraph["{$sub}"] = array();
}
if (!isset($resultGraph["{$sub}"]["{$pred}"])) {
$resultGraph["{$sub}"]["{$pred}"] = array();
}
$resultGraph["{$sub}"]["{$pred}"][] = $obj;
}
}
return $resultGraph;
}