Antevenio/pdo-mysql-select-iterator

<?php
namespace PdoMysqlSelectIterator;

use Predis\Client;

class Factory {
    /**
     * @param \PDO $adapter
     * @param $query
     * @param $blockSize
     * @return Iterator
     * @throws Exception\InvalidQueryException
     */
    public function create(\PDO $adapter, $query, $blockSize)
    {
        if ($this->queryIsLimitable($query) && $blockSize > 0) {
            return new LimitIterator($adapter, $query, $blockSize);
        }
        $adapter->setAttribute(\PDO::ATTR_DEFAULT_FETCH_MODE, \PDO::FETCH_ASSOC);
        $adapter->setAttribute(
            \PDO::ATTR_STATEMENT_CLASS,
            [NativePDOIterator::class, []]
        );
        /** @var Iterator $statement */
        $statement = $adapter->query($query);
        return $statement;
    }

    public function createRedis(\PDO $adapter, $query, Client $predisClient)
    {
        return new RedisIterator($adapter, $query, $predisClient, new UniqueIdGenerator());
    }

    protected function queryIsLimitable($query) {
        return !$this->queryHasARandFunction($query)
            && $this->queryHasOrderByClause($query);
    }

    protected function queryHasARandFunction($query)
    {
        return (preg_match('/RAND\(.*\)/i', $query));
    }

    protected function queryHasOrderByClause($query)
    {
        return (preg_match('/ORDER BY/i', $query));
    }
}