DatabaseInstallLevenshteinCommand.php

<?php

namespace AppBundle\Command;

use Doctrine\ORM\EntityManager;
use Symfony\Component\Console\Command\Command;
use Symfony\Component\Console\Input\InputInterface;
use Symfony\Component\Console\Output\OutputInterface;

class DatabaseInstallLevenshteinCommand extends Command
{
    private $manager;

    public function __construct(EntityManager $manager)
    {
        parent::__construct();

        $this->manager = $manager;
    }

    public function configure()
    {
        $this
            ->setName('database:install-levenshtein')
            ->setDescription('Creates the LEVENSHTEIN command');
    }

    public function execute(InputInterface $input, OutputInterface $output)
    {
        $conn = $this->manager->getConnection();
        $conn->query($this->getQuery());
    }

    public function getQuery()
    {
        $fp = fopen(__FILE__, 'r');

        fseek($fp, __COMPILER_HALT_OFFSET__);

        $query = trim(stream_get_contents($fp));

        fclose($fp);

        return $query;
    }
}

__halt_compiler();

CREATE FUNCTION LEVENSHTEIN(s1 VARCHAR(255), s2 VARCHAR(255)) RETURNS int(11) DETERMINISTIC
BEGIN
    DECLARE s1_len, s2_len, i, j, c, c_temp, cost INT;
    DECLARE s1_char CHAR;
    DECLARE cv0, cv1 VARBINARY(256);
    SET s1_len = CHAR_LENGTH(s1), s2_len = CHAR_LENGTH(s2), cv1 = 0x00, j = 1, i = 1, c = 0;
    IF s1 = s2 THEN
        RETURN 0;
    ELSEIF s1_len = 0 THEN
        RETURN s2_len;
    ELSEIF s2_len = 0 THEN
        RETURN s1_len;
    ELSE
        WHILE j <= s2_len DO
            SET cv1 = CONCAT(cv1, UNHEX(HEX(j))), j = j + 1;
        END WHILE;
        WHILE i <= s1_len DO
            SET s1_char = SUBSTRING(s1, i, 1), c = i, cv0 = UNHEX(HEX(i)), j = 1;
            WHILE j <= s2_len DO
                SET c = c + 1;
                IF s1_char = SUBSTRING(s2, j, 1) THEN SET cost = 0; ELSE SET cost = 1; END IF;
                SET c_temp = CONV(HEX(SUBSTRING(cv1, j, 1)), 16, 10) + cost;
                IF c > c_temp THEN SET c = c_temp; END IF;
                SET c_temp = CONV(HEX(SUBSTRING(cv1, j+1, 1)), 16, 10) + 1;
                IF c > c_temp THEN SET c = c_temp; END IF;
                SET cv0 = CONCAT(cv0, UNHEX(HEX(c))), j = j + 1;
            END WHILE;
            SET cv1 = cv0, i = i + 1;
        END WHILE;
    END IF;
    RETURN c;
END