Query/src/QueryParser.php

128 lines
3.0 KiB
PHP

<?php declare(strict_types=1);
/**
* Query
*
* SQL Query Builder / Database Abstraction Layer
*
* PHP version 7.2
*
* @package Query
* @author Timothy J. Warren <tim@timshomepage.net>
* @copyright 2012 - 2020 Timothy J. Warren
* @license http://www.opensource.org/licenses/mit-license.html MIT License
* @link https://git.timshomepage.net/aviat/Query
* @version 3.0.0
*/
namespace Query;
use Query\Drivers\DriverInterface;
/**
* Utility Class to parse sql clauses for properly escaping identifiers
*/
class QueryParser {
/**
* DB Driver
*
* @var DriverInterface
*/
private $db;
/**
* Regex patterns for various syntax components
*
* @var array
*/
private $matchPatterns = [
'function' => '([a-zA-Z0-9_]+\((.*?)\))',
'identifier' => '([a-zA-Z0-9_-]+\.?)+',
'operator' => '=|AND|&&?|~|\|\|?|\^|/|>=?|<=?|-|%|OR|\+|NOT|\!=?|<>|XOR'
];
/**
* Regex matches
*
* @var array
*/
public $matches = [
'functions' => [],
'identifiers' => [],
'operators' => [],
'combined' => [],
];
/**
* Constructor/entry point into parser
*
* @param DriverInterface $db
*/
public function __construct(DriverInterface $db)
{
$this->db = $db;
}
/**
* Parser method for setting the parse string
*
* @param string $sql
* @return array
*/
public function parseJoin(string $sql): array
{
// Get sql clause components
preg_match_all('`'.$this->matchPatterns['function'].'`', $sql, $this->matches['functions'], PREG_SET_ORDER);
preg_match_all('`'.$this->matchPatterns['identifier'].'`', $sql, $this->matches['identifiers'], PREG_SET_ORDER);
preg_match_all('`'.$this->matchPatterns['operator'].'`', $sql, $this->matches['operators'], PREG_SET_ORDER);
// Get everything at once for ordering
$fullPattern = '`'.$this->matchPatterns['function'].'+|'.$this->matchPatterns['identifier'].'|('.$this->matchPatterns['operator'].')+`i';
preg_match_all($fullPattern, $sql, $this->matches['combined'], PREG_SET_ORDER);
// Go through the matches, and get the most relevant matches
$this->matches = array_map([$this, 'filterArray'], $this->matches);
return $this->matches;
}
/**
* Compiles a join condition after parsing
*
* @param string $condition
* @return string
*/
public function compileJoin(string $condition): string
{
$parts = $this->parseJoin($condition);
$count = count($parts['identifiers']);
// Go through and quote the identifiers
for($i=0; $i <= $count; $i++)
{
if (in_array($parts['combined'][$i], $parts['identifiers']) && ! is_numeric($parts['combined'][$i]))
{
$parts['combined'][$i] = $this->db->quoteIdent($parts['combined'][$i]);
}
}
return implode('', $parts['combined']);
}
/**
* Returns a more useful match array
*
* @param array $array
* @return array
*/
protected function filterArray(array $array): array
{
$newArray = [];
foreach($array as $row)
{
$newArray[] = (is_array($row)) ? $row[0] : $row;
}
return $newArray;
}
}