File Source for SqlGenerator.php

<?php
require_once RDFAPI_INCLUDE_DIR . 'sparql/SparqlEngineDb/TypeSorter.php';
require_once RDFAPI_INCLUDE_DIR . 'sparql/SparqlEngineDb/FilterGenerator.php';
require_once RDFAPI_INCLUDE_DIR . 'sparql/SparqlEngineDb/SqlGeneratorException.php';
/**
* Creates sql statements from a Query object
*
* @author Christian Weiske <cweiske@cweiske.de>
*
* @package sparql
*/
class SparqlEngineDb_SqlGenerator
{
public $query = null;
/**
* Determines which variables can be found
* in which SQL result column.
* @example
* array(
* '?person' => array('t1', 's'),
' '?p' => array('t1', 'p'),
* '?mbox' => array('t2', 'o')
* )
* Would express that variable ?person is the subject
* in result table t1, and ?mbox is the object in
* table t2.
*
* @see $arCreationMethods
*
* @internal The array is created in createSql()
* and used in convertFromDbResult().
*
* @var array
*/
public $arVarAssignments = array();
/**
* Array of variable name => table.col assignments
* for all variables used in the query not only
* the ones that shall be returned.
*
* @example
* array(
* '?person' => 't0.subject'
* )
*
* @var array
*/
public $arUsedVarAssignments = array();
/**
* Array of arrays that contain all variable names
* which are to be found in the result of
* an sql statement in a union.
*
* @example
* array(
* 0 => array(
* '?person' => 's',
* '?p' => 'o'
* ),
* 1 => array(
* '?person' => 's',
* '?mbox' => 'o'
* )
* )
*
* @var array
*/
public $arUnionVarAssignments = array();
/**
* Which variables have been used as which type?
* key is variable name, value is an array of
* max. three keys (s, p, o)
*
* @example
* array(
* '?person' => array(
* 's' => true
* ),
* '?mbox' => array(
* 'o' => true
* )
* )
*
* @var array
*/
protected $arUsedVarTypes = array();
/**
* Array with placeholders of prepared statements variables.
* key is the variable name (without "??"), value is the
* placeholder.
* @var array
*/
protected $arPlaceholders = array();
/**
* Column names for subjects, predicates and
* objects for easy access via their character
* names (spo).
*
* @var array
*/
public static $arTableColumnNames = array(
's' => array(
'value' => 'subject',
'is' => 'subject_is'
),
'p' => array(
'value' => 'predicate'
),
'o' => array(
'value' => 'object',
'is' => 'object_is'
)
);
/**
* Current UNION part number
* @var int
*/
protected $nUnionCount = 0;
protected $nSqlVariableNameCount = 0;
public function __construct(Query $query, ADOConnection $dbConn, $modelID)
{
$this->query = $query;
$this->dbConn = $dbConn;
$this->modelID = $modelID;
}//public function __construct(Query $query, ADOConnection $dbConn, $modelID)
/**
* Creates an SQL query string from the given Sparql query object.
*
* @internal uses $query variable
*
* @return array Array of arrays of SQL query string parts: select, from and where
*
* @throws SparqlEngineDb_SqlGeneratorException If there is no variable in the result set.
*/
function createSql()
{
//var_dump($this->query);
$arSelect = array();
$arFrom = array();
$arWhere = array();
$strResultForm = $this->query->getResultForm();
$filterGen = new SparqlEngineDb_FilterGenerator($this);
switch ($strResultForm) {
case 'construct':
$arResultVars = $this->query->getConstructPatternVariables();
break;
default:
$arResultVars = $this->query->getResultVars();
break;
}
$this->nTableId = 0;
$this->nGraphPatternCount = 0;
$this->nUnionCount = 0;
$this->nUnionTriplePatternCount = 0;
$this->arUnionVarAssignments[0] = array();
foreach ($this->query->getResultPart() as $graphPattern) {
if (self::isEmptyPattern($graphPattern)) {
continue;
}
if ($graphPattern->getUnion() !== null) {
++$this->nUnionCount;
$this->nUnionTriplePatternCount = 0;
$this->nGraphPatternCount = 0;
$this->arUnionVarAssignments[$this->nUnionCount] = array();
}
$this->nTriplePatternCount = 0;
$arTriplePattern = $graphPattern->getTriplePattern();
if ($arTriplePattern != null) {
foreach ($arTriplePattern as $triplePattern) {
list (
$arSelect[$this->nUnionCount][],
$arFrom [$this->nUnionCount][],
$arWhere [$this->nUnionCount][]
) =
$this->getTripleSql(
$triplePattern,
$graphPattern,
$arResultVars
);
++$this->nTableId;
++$this->nTriplePatternCount;
++$this->nUnionTriplePatternCount;
}
}
++$this->nGraphPatternCount;
}
//constraints extra. needed, since OPTIONAL parts are put after
// the current pattern while the constraint already refers to variables
// defined in there
$this->nGraphPatternCount = 0;
$this->nUnionCount = 0;
foreach ($this->query->getResultPart() as $graphPattern) {
if ($graphPattern->getUnion() !== null) {
++$this->nUnionCount;
}
$arConstraints = $graphPattern->getConstraint();
if ($arConstraints != null) {
foreach ($arConstraints as $constraint) {
$arWhere[$this->nUnionCount][count($arWhere[$this->nUnionCount]) - 1]
.= $filterGen->createFilterSql(
$constraint->getTree(),
$graphPattern->getOptional() !== null,
$this->nUnionCount
);
}
}
++$this->nGraphPatternCount;
}
$arSelect = $this->createEqualSelects($arSelect);
$arStrSelect = array();
switch ($strResultForm) {
case 'construct':
case 'describe':
$strSelectType = 'SELECT';
case 'select':
case 'select distinct':
if (!isset($strSelectType)) {
$strSelectType = $strResultForm;
}
foreach ($arSelect as $nUnionCount => $arSelectPart) {
$arSelectPart = self::removeNull($arSelectPart);
if (count($arSelectPart) == 0) {
throw new SparqlEngineDb_SqlGeneratorException('No variable that could be returned.');
}
$arStrSelect[$nUnionCount] = strtoupper($strSelectType) . ' ' . implode(', ' , $arSelectPart);
}
break;
case 'ask':
case 'count':
$strSelect = 'SELECT COUNT(*) as count';
break;
default:
throw new SparqlEngineDb_SqlGeneratorException('Unsupported query type "' . $strResultForm . '"');
break;
}
$arSqls = array();
foreach ($arSelect as $nUnionCount => $arSelectPart) {
$arSqls[] = array(
'select' => $arStrSelect[$nUnionCount],
'from' => ' FROM ' . implode(' ' , self::removeNull($arFrom[$nUnionCount])),
'where' => ' WHERE ' . self::fixWhere(
implode(' ' , self::removeNull($arWhere[$nUnionCount]))
)
);
}
return $arSqls;
}//function createSql()
/**
* 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(QueryTriple $triple, GraphPattern $graphPattern, $arResultVars)
{
$arSelect = array();
$strFrom = null;
$strWhere = null;
$strWhereEquality = '';
$subject = $triple->getSubject();
$predicate = $triple->getPredicate();
$object = $triple->getObject();
$arRefVars = array();
$strTablePrefix = 't' . $this->nTableId;
/**
* SELECT part
* We do select only the columns we need for variables
*/
if (self::isVariable($subject)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$subject])) {
//already selected -> add equality check
$strWhereEquality .= ' AND ' . self::getSqlEqualityCondition(
array($strTablePrefix, 's'),
$this->arVarAssignments[$subject]
);
$this->arUsedVarTypes[$subject]['s'] = true;
} else {
if (isset($this->arVarAssignments[$subject][0])) {
$strTablePrefix = $this->arVarAssignments[$subject][0];
}
$this->arVarAssignments[$subject] = array($strTablePrefix, 's');
$this->arUnionVarAssignments[$this->nUnionCount][$subject] = array($strTablePrefix, 's');
$this->arUsedVarTypes[$subject]['s'] = true;
if (self::isResultVar($subject, $arResultVars)) {
//new variable that needs to be selected
$arSelect[$subject] = array(
$strTablePrefix . '.subject as "' . $strTablePrefix . '.' . $this->getSqlVariableNameValue($subject) . '"',
$strTablePrefix . '.subject_is as "' . $strTablePrefix . '.' . $this->getSqlVariableNameIs($subject) . '"'
);
if (isset($this->arUsedVarAssignments[$subject])) {
$arRefVars[$subject] = $strTablePrefix . '.subject';
} else {
$this->arUsedVarAssignments[$subject] = $strTablePrefix . '.subject';
}
}
}
}
if (self::isVariable($predicate)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$predicate])) {
//already selected -> add equality check
$strWhereEquality .= ' AND ' . self::getSqlEqualityCondition(
array($strTablePrefix, 'p'),
$this->arVarAssignments[$predicate]
);
$this->arUsedVarTypes[$predicate]['p'] = true;
} else {
if (isset($this->arVarAssignments[$predicate][0])) {
$strTablePrefix = $this->arVarAssignments[$predicate][0];
}
$this->arVarAssignments[$predicate] = array($strTablePrefix, 'p');
$this->arUnionVarAssignments[$this->nUnionCount][$predicate] = array($strTablePrefix, 'p');
$this->arUsedVarTypes[$predicate]['p'] = true;
if (self::isResultVar($predicate, $arResultVars)) {
$arSelect[$predicate] = array(
$strTablePrefix . '.predicate as "' . $strTablePrefix . '.' . $this->getSqlVariableNameValue($predicate) . '"'
);
if (isset($this->arUsedVarAssignments[$predicate])) {
$arRefVars[$predicate] = $strTablePrefix . '.predicate';
} else {
$this->arUsedVarAssignments[$predicate] = $strTablePrefix . '.predicate';
}
}
}
}
if (self::isVariable($object)) {
if (isset($this->arUnionVarAssignments[$this->nUnionCount][$object])) {
//already selected -> add equality check
$strWhereEquality .= ' AND ' . self::getSqlEqualityCondition(
array($strTablePrefix, 'o'),
$this->arVarAssignments[$object]
);
$this->arUsedVarTypes[$object]['o'] = true;
} else {
if (isset($this->arVarAssignments[$object][0])) {
$strTablePrefix = $this->arVarAssignments[$object][0];
}
$this->arVarAssignments[$object] = array($strTablePrefix, 'o');
$this->arUnionVarAssignments[$this->nUnionCount][$object] = array($strTablePrefix, 'o');
$this->arUsedVarTypes[$object]['o'] = true;
if (self::isResultVar($object, $arResultVars)) {
$arSelect[$object] = array(
$strTablePrefix . '.object as "' . $strTablePrefix . '.' . $this->getSqlVariableNameValue($object) . '"',
$strTablePrefix . '.object_is as "' . $strTablePrefix . '.' . $this->getSqlVariableNameIs($object) . '"',
$strTablePrefix . '.l_language as "' . $strTablePrefix . '.' . $this->getSqlVariableNameLanguage($object) . '"',
$strTablePrefix . '.l_datatype as "' . $strTablePrefix . '.' . $this->getSqlVariableNameDatatype($object) . '"',
);
if (isset($this->arUsedVarAssignments[$object])) {
$arRefVars[$object] = $strTablePrefix . '.object';
} else {
$this->arUsedVarAssignments[$object] = $strTablePrefix . '.object';
}
}
if (isset($this->query->varLanguages[$object])
&& $this->query->varLanguages[$object] !== null
) {
$strWhereEquality .=
' AND ' . $strTablePrefix . '.l_language = "'
. addslashes($this->query->varLanguages[$object]) . '"';
}
if (isset($this->query->varDatatypes[$object])
&& $this->query->varDatatypes[$object] !== null
) {
$strWhereEquality .=
' AND ' . $strTablePrefix . '.l_datatype = "'
. addslashes($this->query->varDatatypes[$object]) . '"';
}
}
}
/**
* FROM part
*/
if ($this->nUnionTriplePatternCount == 0) {
//first FROM
$strFrom = 'statements as ' . $strTablePrefix;
} else {
//normal join
$strFrom = 'LEFT JOIN statements as ' . $strTablePrefix
. ' ON t0.modelID = ' . $strTablePrefix . '.modelID';
foreach ($arRefVars as $strRefVar => $strSqlVar) {
$strFrom .= ' AND ' . $this->arUsedVarAssignments[$strRefVar] . ' = ' . $strSqlVar;
}
if ($graphPattern->getOptional() !== null) {
$strFrom .= $this->getSqlCondition($subject , $strTablePrefix, 'subject')
. $this->getSqlCondition($predicate, $strTablePrefix, 'predicate')
. $this->getSqlCondition($object , $strTablePrefix, 'object')
. $strWhereEquality;
}
}
/**
* WHERE part
*/
if ($this->nUnionTriplePatternCount == 0) {
$strWhere = $strTablePrefix . '.modelID = ' . intval($this->modelID);
}
if ($graphPattern->getOptional() === null || $this->nGraphPatternCount == 0) {
$strWhere .= $this->getSqlCondition($subject , $strTablePrefix, 'subject')
. $this->getSqlCondition($predicate, $strTablePrefix, 'predicate')
. $this->getSqlCondition($object , $strTablePrefix, 'object')
. $strWhereEquality;
}
return array($arSelect, $strFrom, $strWhere);
}//function getTripleSql(QueryTriple $triple)
/**
* Creates SELECT statements that have the same number of columns.
* Needed for UNIONs.
*
* @param array $arSelect Array of arrays.
* array(
* //for each union part one
* 0 => array(
* //foreach triple pattern
* 0 => array(
* '?person' => array(
* 't0.subject as "t0.subject"'
* )
* )
* )
* )
* @return array Array of SELECT strings
*/
protected function createEqualSelects($arSelect)
{
$arNewSelect = array();
if (count($arSelect) == 1) {
foreach ($arSelect[0] as $arTripleVars) {
$ar = array();
foreach ($arTripleVars as $arVarParts) {
$ar[] = implode(', ', $arVarParts);
}
if (count($ar) > 0) {
$arNewSelect[0][] = implode(', ', $ar);
}
}
return $arNewSelect;
}
$arVars = array();
foreach ($arSelect as $arUnionVars) {
foreach ($arUnionVars as $arTripleVars) {
$arVars = array_merge($arVars, array_keys($arTripleVars));
}
}
$arVars = array_unique($arVars);
foreach ($arSelect as $nUnionCount => $arUnionVars) {
$arSelectVars = array();
foreach ($arUnionVars as $arTripleVars) {
foreach ($arTripleVars as $strVar => $arVarParts) {
$arSelectVars[$strVar] = $arVarParts;
}
}
$ars = array();
foreach ($arVars as $strVar) {
if (isset($arSelectVars[$strVar])) {
$ar = $arSelectVars[$strVar];
$nCount = count($arSelectVars[$strVar]);
} else {
$ar = array();
$nCount = 0;
}
if ($nCount == 0) {
//nothing of this variable in this union part
$ar[] = 'NULL as '
. '"' . $this->arVarAssignments[$strVar][0] . '.' . $this->arVarAssignments[$strVar]['sql_value'] . '"';
}
if ((
isset($this->arUsedVarTypes[$strVar]['o'])
|| isset($this->arUsedVarTypes[$strVar]['s'])
) && $nCount < 2
) {
//it's a subject or object, but we don't want the type
$ar[] = 'NULL as '
. '"' . $this->arVarAssignments[$strVar][0] . '.' . $this->arVarAssignments[$strVar]['sql_is'] . '"';
}
if (isset($this->arUsedVarTypes[$strVar]['o']) && $nCount < 4) {
//it's a subject or object, but we don't want the type
if (isset($this->arVarAssignments[$strVar]['sql_lang'])) {
$strColLanguage = $this->arVarAssignments[$strVar]['sql_lang'];
} else {
$strColLanguage = 'dummyLang';
}
if (isset($this->arVarAssignments[$strVar]['sql_type'])) {
$strColDatatype = $this->arVarAssignments[$strVar]['sql_type'];
} else {
$strColDatatype = 'dummyType';
}
$ar[] = 'NULL as '
. '"' . $this->arVarAssignments[$strVar][0] . '.' . $strColLanguage . '"';
$ar[] = 'NULL as '
. '"' . $this->arVarAssignments[$strVar][0] . '.' . $strColDatatype . '"';
}
$ars[] = implode(', ', $ar);
}
$arNewSelect[$nUnionCount] = $ars;
}
return $arNewSelect;
}//protected function createEqualSelects($arSelect)
/**
* 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 (self::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)';
$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)
);
}
}//function getSqlCondition($bject, $strTablePrefix, $strType)
/**
* Checks if the sentence part (subject, predicate or object) in
* $arNew has the same content as $arOld.
* Required for queries like ":x ?a ?a" where predicate and object
* need to have the same value
*
* @param array $arNew array($strTablePrefix, $strType = s|p|o)
* @param array $arOld array($strTablePrefix, $strType = s|p|o)
* @return string
*/
protected static function getSqlEqualityCondition($arNew, $arOld)
{
$chTypeNew = $arNew[1]; $chTypeOld = $arOld[1];
$strTablePrefixNew = $arNew[0]; $strTablePrefixOld = $arOld[0];
if ($chTypeNew == 'p' || $chTypeOld == 'p') {
//just check value
//FIXME: it might be I need to check for resource type in object and subject
return
$strTablePrefixNew . '.' . self::$arTableColumnNames[$chTypeNew]['value']
. ' = '
. $strTablePrefixOld . '.' . self::$arTableColumnNames[$chTypeOld]['value']
;
} else if ($chTypeNew == 's' || $chTypeOld == 's') {
//check value and type
return
$strTablePrefixNew . '.' . self::$arTableColumnNames[$chTypeNew]['value']
. ' = '
. $strTablePrefixOld . '.' . self::$arTableColumnNames[$chTypeOld]['value']
. ' AND '
. $strTablePrefixNew . '.' . self::$arTableColumnNames[$chTypeNew]['is']
. ' = '
. $strTablePrefixOld . '.' . self::$arTableColumnNames[$chTypeOld]['is']
;
} else {
//two objects -> check everything
return
$strTablePrefixNew . '.object = ' . $strTablePrefixOld . '.object'
. ' AND '
. $strTablePrefixNew . '.object_is = ' . $strTablePrefixOld . '.object_is'
. ' AND '
. $strTablePrefixNew . '.l_language = ' . $strTablePrefixOld . '.l_language'
. ' AND '
. $strTablePrefixNew . '.l_datatype = ' . $strTablePrefixOld . '.l_datatype'
;
}
}//protected static function getSqlEqualityCondition($arNew, $arOld)
/**
* Checks if the given variable name is part of the result
* variables list.
* Needed since $arResultVars may contain "*" that captures all variables.
*
* @param string $strVar Variable name (e.g. "?p")
* @param array $arResultVars Array with result variables
* @return boolean true if it is a result variable
*/
protected static function isResultVar($strVar, &$arResultVars)
{
return in_array('*', $arResultVars) || in_array($strVar, $arResultVars);
}//protected static function isResultVar($strVar, &$arResultVars)
/**
* Checks if the given subject/predicate/object
* is a variable name.
*
* @return boolean
*/
public static function isVariable($bject)
{
return is_string($bject) && strlen($bject) >= 2
&& ($bject[0] == '?' || $bject[0] == '$');
}//public static function isVariable($bject)
/**
* Checks if the given variable is a replacement
* for a prepared statement.
*
* @return boolean
*/
public static function isPreparedVariable($bject)
{
return is_string($bject) && strlen($bject) >= 3
&& ($bject[0] == '?' || $bject[0] == '$')
&& ($bject[1] == '?' || $bject[1] == '$')
;
}//public static function isPreparedVariable($bject)
/**
* Returns a placeholder to be included in the sql statement.
* It will be replaced with a real prepared statement variable later on.
* Also adds it to the internal placeholder array.
*
* @param string $strVariable The variable to get a placeholder for
* @return string placeholder
*/
protected function getPreparedVariablePlaceholder($strVariable)
{
$strName = substr($strVariable, 2);
if (!isset($this->arPlaceholders[$strName])) {
$this->arPlaceholders[$strName] = '@$%_PLACEHOLDER_'
. count($this->arPlaceholders) . '_%$@';
}
return $this->arPlaceholders[$strName];
}//protected function getPreparedVariablePlaceholder($strVariable)
public function getPlaceholders()
{
return $this->arPlaceholders;
}//public function getPlaceholders()
public function getVarAssignments()
{
return $this->arVarAssignments;
}//public function getVarAssignments()
public function getUsedVarAssignments()
{
return $this->arUsedVarAssignments;
}//public function getUsedVarAssignments()
public function getUsedVarTypes()
{
return $this->arUsedVarTypes;
}//public function getUsedVarTypes()
/**
* Checks if the graph pattern is empty (contains no
* usable data).
* Occurs when using "{}" without pre- or suffixes
* WHERE
* {
* { ?person rdf:type foaf:Person } .
* }
*
* @param GraphPattern $graphPattern Graph pattern to check
* @return boolean True if the pattern is empty.
*/
protected static function isEmptyPattern(GraphPattern $graphPattern)
{
return
$graphPattern->getTriplePattern() === false
&& $graphPattern->getGraphname() === null
&& $graphPattern->getConstraint() === false
&& $graphPattern->getOptional() === null
&& $graphPattern->getUnion() === null
;
}//protected static function isEmptyPattern(GraphPattern $graphPattern)
/**
* Removes all NULL values from an array and returns it.
*
* @param array $array Some array
* @return array $array without the NULL values.
*/
protected static function removeNull($array)
{
foreach ($array as $key => &$value) {
if ($value === null) {
unset($array[$key]);
}
}
return $array;
}//protected static function removeNull($array)
/**
* Removes a leading AND from the where clause which would render
* the sql illegal.
*/
protected function fixWhere($strWhere)
{
$strWhere = ltrim($strWhere);
if (substr($strWhere, 0, 4) == 'AND ') {
$strWhere = substr($strWhere, 4);
}
return $strWhere;
}//protected function fixWhere($strWhere)
protected function getSqlVariableName($strSparqlVar)
{
if (!isset($this->arVarAssignments[$strSparqlVar]['sqlname'])) {
if (preg_match('/[a-zA-Z0-9]+/', substr($strSparqlVar, 1))) {
$strName = 'v_' . substr($strSparqlVar, 1);
} else {
$strName = 'va_' . $this->nSqlVariableNameCount++;
}
$this->arVarAssignments[$strSparqlVar]['sqlname'] = $strName;
}
return $this->arVarAssignments[$strSparqlVar]['sqlname'];
}//protected function getSqlVariableName($strSparqlVar)
protected function getSqlVariableNameValue($strSparqlVar)
{
$this->arVarAssignments[$strSparqlVar]['sql_value'] =
'value_' . $this->getSqlVariableName($strSparqlVar);
return $this->arVarAssignments[$strSparqlVar]['sql_value'];
}//protected function getSqlVariableNameValue($strSparqlVar)
protected function getSqlVariableNameIs($strSparqlVar)
{
$this->arVarAssignments[$strSparqlVar]['sql_is'] =
'is_' . $this->getSqlVariableName($strSparqlVar);
return $this->arVarAssignments[$strSparqlVar]['sql_is'];
}//protected function getSqlVariableNameIs($strSparqlVar)
protected function getSqlVariableNameLanguage($strSparqlVar)
{
$this->arVarAssignments[$strSparqlVar]['sql_lang'] =
'lang_' . $this->getSqlVariableName($strSparqlVar);
return $this->arVarAssignments[$strSparqlVar]['sql_lang'];
}//protected function getSqlVariableNameLanguage($strSparqlVar)
protected function getSqlVariableNameDatatype($strSparqlVar)
{
$this->arVarAssignments[$strSparqlVar]['sql_type'] =
'type_' . $this->getSqlVariableName($strSparqlVar);
return $this->arVarAssignments[$strSparqlVar]['sql_type'];
}//protected function getSqlVariableNameDatatype($strSparqlVar)
}//class SparqlEngineDb_SqlGenerator
?>

Documentation generated on Fri, 1 Jun 2007 16:52:24 +0200 by phpDocumentor 1.3.2

Source for file SqlGenerator.php