backup php to file .sql and zip file

backup.php

<?php
ini_set('max_execution_time', '0');
ini_set('memory_limit', '-1');

$backupdir = "backup/";//folder backup file
$host = "";//host / ip database
$root = "";//user database
$pass = "";//password database
$db_name = "";//name database
$set_name = "utf8mb4";
$mysqli = new mysqli($host, $root, $pass, $db_name);
$mysqli->select_db($db_name);
$mysqli->query("SET NAMES '" . $set_name . "'");

//get table list
$queryTables    = $mysqli->query("SHOW FULL TABLES WHERE Table_Type = 'BASE TABLE';");
while ($row = $queryTables->fetch_row()) {
    $target_tables[] = $row[0];
}

//get table structure
foreach ($target_tables as $table) {
    $result = $mysqli->query("SELECT * FROM " . $table);
    $fields_amount = $result->field_count;
    $rows_num = $mysqli->affected_rows;
    $res = $mysqli->query("SHOW CREATE TABLE " . $table);
    $TableMLine = $res->fetch_row();
    $content = (!isset($content) ?  '' : $content) . "\n\nDROP TABLE IF EXISTS `" . $table . "`;\n" . $TableMLine[1] . ";\n\n";

    for ($i = 0, $st_counter = 0; $i < $fields_amount; $i++, $st_counter = 0) {
        while ($row = $result->fetch_row()) { //when started (and every after 100 command cycle):
            if ($st_counter % 100 == 0 || $st_counter == 0) {
                $content .= "\nINSERT INTO " . $table . " VALUES";
            }
            $content .= "\n(";
            for ($j = 0; $j < $fields_amount; $j++) {
                $row[$j] = str_replace(array("\r\n\r\n", "\n\r\n", "\r\n", "\n\n", "\n"), array("\\r\\n", "\\r\\n", "\\r\\n", "\\r\\n", "\\r\\n"), addslashes($row[$j]));
                if (isset($row[$j])) {
                    $content .= '"' . $row[$j] . '"';
                } else {
                    $content .= '""';
                }
                if ($j < ($fields_amount - 1)) {
                    $content .= ',';
                }
            }
            $content .= ")";
            //every after 100 command cycle [or at last line] ....p.s. but should be inserted 1 cycle eariler
            if ((($st_counter + 1) % 100 == 0 && $st_counter != 0) || $st_counter + 1 == $rows_num) {
                $content .= ";";
            } else {
                $content .= ",";
            }
            $st_counter = $st_counter + 1;
        }
    }
    $content .= "\n\n";
}

//get view list
$queryViews    = $mysqli->query("SHOW FULL TABLES WHERE Table_Type = 'VIEW';");
while ($row = $queryViews->fetch_row()) {
    $target_views[] = $row[0];
}
//get view structure
foreach ($target_views as $view) {
    $selectViews = $mysqli->query("SELECT VIEW_DEFINITION FROM INFORMATION_SCHEMA.VIEWS WHERE TABLE_NAME = '" . $view . "';");
    while ($row = $selectViews->fetch_row()) {
        $content .= "DROP VIEW IF EXISTS `" . $view . "`;" . "\n";
        $select_data = str_replace("`" . $db_name . "`.", '', $row[0]);
        $content .= "CREATE ALGORITHM = UNDEFINED SQL SECURITY DEFINER VIEW `" . $view . "` AS " . $select_data . ";" . "\n\n";
    }
}
// save as .sql file
//give additional description
$content_ = "\n-- Database Backup --\n";
$content_ .= "-- Ver. : 1.0.2\n";
$content_ .= "-- Host : 127.0.0.1\n";
$content_ .= "-- Generating Time : " . date("M d") . ", " . date("Y") . " at " . date("H:i:s:") . date("A") . "\n\n";
$content_ .= "\n" . "SET NAMES " . $set_name . ";";
$content_ .= "\n" . "SET FOREIGN_KEY_CHECKS = 0;";
$content_ .= $content;
$content_ .= "\n\n" . "SET FOREIGN_KEY_CHECKS = 1;";
$content_ .= "\n";

//save the file
$filename = $db_name . " " . date("Y-m-d H-i-s") . ".sql";
$backup_file_name = $backupdir . $filename;
$fp = fopen($backup_file_name, 'w+');
$result = fwrite($fp, $content_);
fclose($fp);

$zip = new ZipArchive;
if ($zip->open($backup_file_name . '.zip', ZipArchive::CREATE) === TRUE) {
    // Add file to the zip file
    $zip->addFile($backup_file_name, $filename);
    $zip->close();
    unlink($backup_file_name);
}

echo json_encode([
    "metadata" => [
        "code" => 200,
        "message" => "OK",
    ]
]);
// //download file directly from browser
// $file_path = $backup_file_name;
// if (!empty($file_path) && file_exists($file_path)) {
//     header("Pragma:public");
//     header("Expired:0");
//     header("Cache-Control:must-revalidate");
//     header("Content-Control:public");
//     header("Content-Description: File Transfer");
//     header("Content-Type: application/octet-stream");
//     header("Content-Disposition:attachment; filename=\"" . basename($file_path) . "\"");
//     header("Content-Transfer-Encoding:binary");
//     header("Content-Length:" . filesize($file_path));
//     flush();
//     readfile($file_path);
//     exit();
// }