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2007-05-14 23:04:32 +00:00

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PHP

<?php
/*
* $Id: Query.php 1296 2007-04-26 17:42:03Z zYne $
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* and is licensed under the LGPL. For more information, see
* <http://www.phpdoctrine.com>.
*/
/**
* Doctrine_Query_Parser
*
* @package Doctrine
* @license http://www.opensource.org/licenses/lgpl-license.php LGPL
* @category Object Relational Mapping
* @link www.phpdoctrine.com
* @since 1.0
* @version $Revision: 1296 $
* @author Konsta Vesterinen <kvesteri@cc.hut.fi>
*/
class Doctrine_Query_Parser
{
/**
* getQueryBase
* returns the base of the generated sql query
* On mysql driver special strategy has to be used for DELETE statements
*
* @return string the base of the generated sql query
*/
public function getQueryBase()
{
switch ($this->type) {
case self::DELETE:
$q = 'DELETE FROM ';
break;
case self::UPDATE:
$q = 'UPDATE ';
break;
case self::SELECT:
$distinct = ($this->isDistinct()) ? 'DISTINCT ' : '';
$q = 'SELECT ' . $distinct . implode(', ', $this->parts['select']) . ' FROM ';
break;
}
return $q;
}
/**
* buildFromPart
*
* @return string
*/
public function buildFromPart()
{
foreach ($this->parts['from'] as $k => $part) {
if ($k === 0) {
$q .= $part;
continue;
}
// preserve LEFT JOINs only if needed
if (substr($part, 0, 9) === 'LEFT JOIN') {
$e = explode(' ', $part);
$aliases = array_merge($this->subqueryAliases,
array_keys($this->neededTables));
if( ! in_array($e[3], $aliases) &&
! in_array($e[2], $aliases) &&
! empty($this->pendingFields)) {
continue;
}
}
$e = explode(' ON ', $part);
// we can always be sure that the first join condition exists
$e2 = explode(' AND ', $e[1]);
$part = $e[0] . ' ON ' . array_shift($e2);
if ( ! empty($e2)) {
$parser = new Doctrine_Query_JoinCondition($this);
$part .= ' AND ' . $parser->parse(implode(' AND ', $e2));
}
$q .= ' ' . $part;
}
}
/**
* builds the sql query from the given parameters and applies things such as
* column aggregation inheritance and limit subqueries if needed
*
* @param array $params an array of prepared statement params (needed only in mysql driver
* when limit subquery algorithm is used)
* @return string the built sql query
*/
public function getQuery($params = array())
{
if (empty($this->parts['select']) || empty($this->parts['from'])) {
return false;
}
$needsSubQuery = false;
$subquery = '';
$k = array_keys($this->_aliasMap);
$table = $this->_aliasMap[$k[0]]['table'];
if( ! empty($this->parts['limit']) && $this->needsSubquery && $table->getAttribute(Doctrine::ATTR_QUERY_LIMIT) == Doctrine::LIMIT_RECORDS) {
$needsSubQuery = true;
$this->limitSubqueryUsed = true;
}
// process all pending SELECT part subqueries
$this->processPendingSubqueries();
// build the basic query
$str = '';
if($this->isDistinct()) {
$str = 'DISTINCT ';
}
$q = $this->getQueryBase();
$q .= $this->buildFrom();
if ( ! empty($this->parts['set'])) {
$q .= ' SET ' . implode(', ', $this->parts['set']);
}
$string = $this->applyInheritance();
if ( ! empty($string)) {
$this->parts['where'][] = '(' . $string . ')';
}
$modifyLimit = true;
if ( ! empty($this->parts["limit"]) || ! empty($this->parts["offset"])) {
if($needsSubQuery) {
$subquery = $this->getLimitSubquery();
switch(strtolower($this->conn->getName())) {
case 'mysql':
// mysql doesn't support LIMIT in subqueries
$list = $this->conn->execute($subquery, $params)->fetchAll(PDO::FETCH_COLUMN);
$subquery = implode(', ', $list);
break;
case 'pgsql':
// pgsql needs special nested LIMIT subquery
$subquery = 'SELECT doctrine_subquery_alias.' . $table->getIdentifier(). ' FROM (' . $subquery . ') AS doctrine_subquery_alias';
break;
}
$field = $this->aliasHandler->getShortAlias($table->getTableName()) . '.' . $table->getIdentifier();
// only append the subquery if it actually contains something
if($subquery !== '') {
array_unshift($this->parts['where'], $field. ' IN (' . $subquery . ')');
}
$modifyLimit = false;
}
}
$q .= ( ! empty($this->parts['where']))? ' WHERE ' . implode(' AND ', $this->parts['where']):'';
$q .= ( ! empty($this->parts['groupby']))? ' GROUP BY ' . implode(', ', $this->parts['groupby']):'';
$q .= ( ! empty($this->parts['having']))? ' HAVING ' . implode(' AND ', $this->parts['having']):'';
$q .= ( ! empty($this->parts['orderby']))? ' ORDER BY ' . implode(', ', $this->parts['orderby']):'';
if ($modifyLimit) {
$q = $this->conn->modifyLimitQuery($q, $this->parts['limit'], $this->parts['offset']);
}
// return to the previous state
if ( ! empty($string)) {
array_pop($this->parts['where']);
}
if ($needsSubQuery) {
array_shift($this->parts['where']);
}
return $q;
}
/**
* getLimitSubquery
* this is method is used by the record limit algorithm
*
* when fetching one-to-many, many-to-many associated data with LIMIT clause
* an additional subquery is needed for limiting the number of returned records instead
* of limiting the number of sql result set rows
*
* @return string the limit subquery
*/
public function getLimitSubquery()
{
$k = array_keys($this->tables);
$table = $this->tables[$k[0]];
// get short alias
$alias = $this->aliasHandler->getShortAlias($table->getTableName());
$primaryKey = $alias . '.' . $table->getIdentifier();
// initialize the base of the subquery
$subquery = 'SELECT DISTINCT ' . $primaryKey;
if ($this->conn->getDBH()->getAttribute(PDO::ATTR_DRIVER_NAME) == 'pgsql') {
// pgsql needs the order by fields to be preserved in select clause
foreach ($this->parts['orderby'] as $part) {
$e = explode(' ', $part);
// don't add primarykey column (its already in the select clause)
if ($e[0] !== $primaryKey) {
$subquery .= ', ' . $e[0];
}
}
}
$subquery .= ' FROM ' . $this->conn->quoteIdentifier($table->getTableName()) . ' ' . $alias;
foreach ($this->parts['join'] as $parts) {
foreach ($parts as $part) {
// preserve LEFT JOINs only if needed
if (substr($part,0,9) === 'LEFT JOIN') {
$e = explode(' ', $part);
if ( ! in_array($e[3], $this->subqueryAliases) &&
! in_array($e[2], $this->subqueryAliases)) {
continue;
}
}
$subquery .= ' '.$part;
}
}
// all conditions must be preserved in subquery
$subquery .= ( ! empty($this->parts['where']))? ' WHERE ' . implode(' AND ', $this->parts['where']) : '';
$subquery .= ( ! empty($this->parts['groupby']))? ' GROUP BY ' . implode(', ', $this->parts['groupby']) : '';
$subquery .= ( ! empty($this->parts['having']))? ' HAVING ' . implode(' AND ', $this->parts['having']) : '';
$subquery .= ( ! empty($this->parts['orderby']))? ' ORDER BY ' . implode(', ', $this->parts['orderby']) : '';
// add driver specific limit clause
$subquery = $this->conn->modifyLimitQuery($subquery, $this->parts['limit'], $this->parts['offset']);
$parts = self::quoteExplode($subquery, ' ', "'", "'");
foreach($parts as $k => $part) {
if(strpos($part, "'") !== false) {
continue;
}
if($this->aliasHandler->hasAliasFor($part)) {
$parts[$k] = $this->aliasHandler->generateNewAlias($part);
}
if(strpos($part, '.') !== false) {
$e = explode('.', $part);
$trimmed = ltrim($e[0], '( ');
$pos = strpos($e[0], $trimmed);
$e[0] = substr($e[0], 0, $pos) . $this->aliasHandler->generateNewAlias($trimmed);
$parts[$k] = implode('.', $e);
}
}
$subquery = implode(' ', $parts);
return $subquery;
}
/**
* tokenizeQuery
* splits the given dql query into an array where keys
* represent different query part names and values are
* arrays splitted using sqlExplode method
*
* example:
*
* parameter:
* $query = "SELECT u.* FROM User u WHERE u.name LIKE ?"
* returns:
* array('select' => array('u.*'),
* 'from' => array('User', 'u'),
* 'where' => array('u.name', 'LIKE', '?'))
*
* @param string $query DQL query
* @throws Doctrine_Query_Exception if some generic parsing error occurs
* @return array an array containing the query string parts
*/
public function tokenizeQuery($query)
{
$e = Doctrine_Tokenizer::sqlExplode($query, ' ');
foreach($e as $k=>$part) {
$part = trim($part);
switch(strtolower($part)) {
case 'delete':
case 'update':
case 'select':
case 'set':
case 'from':
case 'where':
case 'limit':
case 'offset':
case 'having':
$p = $part;
$parts[$part] = array();
break;
case 'order':
case 'group':
$i = ($k + 1);
if(isset($e[$i]) && strtolower($e[$i]) === "by") {
$p = $part;
$parts[$part] = array();
} else
$parts[$p][] = $part;
break;
case "by":
continue;
default:
if( ! isset($p))
throw new Doctrine_Query_Exception("Couldn't parse query.");
$parts[$p][] = $part;
}
}
return $parts;
}
/**
* DQL PARSER
* parses a DQL query
* first splits the query in parts and then uses individual
* parsers for each part
*
* @param string $query DQL query
* @param boolean $clear whether or not to clear the aliases
* @throws Doctrine_Query_Exception if some generic parsing error occurs
* @return Doctrine_Query
*/
public function parseQuery($query, $clear = true)
{
if ($clear) {
$this->clear();
}
$query = trim($query);
$query = str_replace("\n", ' ', $query);
$query = str_replace("\r", ' ', $query);
$parts = $this->tokenizeQuery($query);
foreach($parts as $k => $part) {
$part = implode(' ', $part);
switch(strtolower($k)) {
case 'create':
$this->type = self::CREATE;
break;
case 'insert':
$this->type = self::INSERT;
break;
case 'delete':
$this->type = self::DELETE;
break;
case 'select':
$this->type = self::SELECT;
$this->parseSelect($part);
break;
case 'update':
$this->type = self::UPDATE;
$k = 'FROM';
case 'from':
$class = 'Doctrine_Query_' . ucwords(strtolower($k));
$parser = new $class($this);
$parser->parse($part);
break;
case 'set':
$class = 'Doctrine_Query_' . ucwords(strtolower($k));
$parser = new $class($this);
$this->parts['set'][] = $parser->parse($part);
break;
case 'group':
case 'order':
$k .= 'by';
case 'where':
case 'having':
$class = 'Doctrine_Query_' . ucwords(strtolower($k));
$parser = new $class($this);
$name = strtolower($k);
$this->parts[$name][] = $parser->parse($part);
break;
case 'limit':
$this->parts['limit'] = trim($part);
break;
case 'offset':
$this->parts['offset'] = trim($part);
break;
}
}
return $this;
}
}