Large insert query SQL builder

insert-query-packet-limit.php

<?php
/**
 * @link http://stackoverflow.com/questions/9719032/php-insert-array-into-db-i-know-there-already-posts-existing-but
 */

/**
 * Insert Query SQL Builder based on packed size limits
 */
class SQLInsertQuery
{
    /**
     * @var string
     */
    private $base;

    /**
     * @var string
     */
    private $sql;

    /**
     * @var int
     */
    private $delta;

    /**
     * @var int
     */
    private $limit;

    /**
     * @var int
     */
    private $count;

    /**
     * @param string $base
     * @param int $limit
     * @param int $delta additional bytes for length calculation
     */
    public function __construct($base, $limit, $delta = 10) {
        $this->base = $base;
        $this->limit = $limit;
        $this->delta = $delta;
        $this->resetQuery();
    }
    public function resetQuery() {
        $this->sql = $this->base;
        $this->count = 0;
    }
    /**
     * @param string $sqlFragment
     * @return bool
     */
    public function willQuery($sqlFragment) {
        return $this->isAboveLimit($this->sql . $sqlFragment);
    }
    /**
     * @param string $sql
     * @return bool
     */
    private function isAboveLimit($sql) {
        return strlen($sql) + $this->delta > $this->limit;
    }
    /**
     * @param string $sql
     */
    public function addSQL($sql) {
        $separator = ',';
        if ($this->willQuery($sql)) {
            $this->query();
        }
        if ($this->count++) $sql = $separator . $sql;
        $this->sql .= $sql;
    }
    public function query() {
        if (!$this->count) {
            return; # nothing to do
        }
        $sql = $this->sql . ';';
        // do your mysql query here.
        printf("Running: %s\n", $sql);
        $this->resetQuery();
    }
    /**
     * @param array $row
     */
    public function addRow(array $row) {
        $values = $this->encodeRow($row);
        $pair   = $this->buildPair($values);
        $this->addSQL($pair);
    }
    private function encodeRow(array $row) {
        foreach($row as &$value) {
            // e.g.:
            // $value = sprintf("'%s'", mysqli_real_escape_string($value));
            // according to the row value types.
            $value = sprintf("'%s'", $value); # this example is w/o mysqli
        }
        unset($value);
        return $row;
    }
    private function buildPair($values) {
        return sprintf('(%s)', implode(',', $values));
    }
}


# sample data
$data = array(
    array('city1', 'code', 'country'),
    array('city2', 'code', 'country'),
    array('city3', 'code', 'country'),
    array('city4', 'code', 'country'),
    array('city5', 'code', 'country'),
    array('city6', 'code', 'country'),
    array('city7', 'code', 'country'),
);

$max_allowed_packet = 1048576; # mysql default value
$max_allowed_packet = 128; # for demonstration purposes
$sql = new SQLInsertQuery('INSERT INTO test (t_city, t_code, t_country) VALUES ', $max_allowed_packet);
foreach($data as $row) { # any iterator data-set provider does work
    $sql->addRow($row);
}
$sql->query();  # manually query any potential left-over query.