/**
* Creates an SQL statement that checks for the value
* of some subject/predicate/object
*
* @param mixed $bject subject|predicate|object
* @param string $strTablePrefix Table prefix (e.g. "t0")
* @param string $strType Type of $bject ('subject'|'predicate'|'object')
* @return string Part of the SQL query (prefixed with AND)
*/
function getSqlCondition($bject, $strTablePrefix, $strType)
{
if (is_string($bject)) {
if (SparqlVariable::isVariable($bject)) {
//variable?
if (self::isPreparedVariable($bject)) {
//no, not really
$value = $this->getPreparedVariablePlaceholder($bject);
} else {
//yes
return null;
}
} else {
$value = $this->dbConn->qstr($bject);
}
//literal
return ' AND ' . $strTablePrefix . '.' . $strType . ' = ' . $value;
}
if ($bject instanceof BlankNode) {
//Blank node
throw new SparqlEngineDb_SqlGeneratorException('FIXME: Querying for blank nodes not supported');
} else {
if ($bject instanceof Resource) {
//Resource
$r = ' AND ' . $strTablePrefix . '.' . $strType . ' = ' . $this->dbConn->qstr($bject->getURI());
if ($strType !== 'predicate') {
$r .= ' AND ' . $strTablePrefix . '.' . $strType . '_is =' . ' "r"';
}
return $r;
} else {
if ($bject instanceof Literal) {
//Literal
//I'm doubling Filter code here, but what the hell
$strColDatatype = $strTablePrefix . '.l_datatype';
if ($bject->dtype == 'http://www.w3.org/2001/XMLSchema#integer' || $bject->dtype == 'http://www.w3.org/2001/XMLSchema#double') {
$strVariable = 'CAST(' . $strTablePrefix . '.' . $strType . ' AS DECIMAL(15,10))';
$strValue = $bject->getLabel();
} else {
$strVariable = $strTablePrefix . '.' . $strType;
$strValue = $this->dbConn->qstr($bject->getLabel());
}
$r = ' AND ' . $strVariable . ' = ' . $strValue;
if ($strType !== 'predicate') {
$r .= ' AND ' . $strTablePrefix . '.' . $strType . '_is =' . ' "l"';
}
if ($strType == 'object') {
if ($bject->dtype == '' || $bject->dtype == 'http://www.w3.org/2001/XMLSchema#string') {
//string
$r .= ' AND (' . $strColDatatype . ' = ""' . ' OR ' . $strColDatatype . ' = "http://www.w3.org/2001/XMLSchema#string"' . ')';
} else {
$r .= ' AND ' . $strColDatatype . ' = "' . $bject->dtype . '"';
}
}
if ($bject->lang != '') {
$strColLanguage = $strTablePrefix . '.l_language';
$r .= ' AND ' . $strColLanguage . ' = ' . $this->dbConn->qstr($bject->lang);
}
return $r;
} else {
throw new SparqlEngineDb_SqlGeneratorException('Unsupported sentence part: ' . get_class($bject));
}
}
}
}
/**
* Checks if the given tree element is a variable
*
* @param array $tree Tree element
* @return boolean True if the element is a variable
*/
protected function isVariable($tree)
{
return $tree['type'] == 'value' && $tree['quoted'] === false && SparqlVariable::isVariable($tree['value']) && isset($this->sg->arUnionVarAssignments[$this->nUnionCount][$tree['value']]);
}
/**
* Returns an array of all variables in this triple.
*
* @return array Array of variable names
*/
public function getVariables()
{
$arVars = array();
foreach (array('subject', 'predicate', 'object') as $strVar) {
if (SparqlVariable::isVariable($this->{$strVar})) {
$arVars[] = $this->{$strVar};
}
}
return $arVars;
}
