Daily backups, keep 30: php / mysql, works on hosts that don't have mysqldump

backup.php

<?php
// Database connection information

$dbhost = 'localhost';
$dbuser = '';
$dbpass = '';
$dbname = '';

// Backup folder location
$backup_folder = '/path/backups';

// Create a timestamp for the current date
$date = date('Y-m-d');

// Create a filename for the backup file with the timestamp
$backup_filename = $backup_folder . '/' . $dbname . '_' . $date . '.sql';

// Connect to the database
$conn = mysqli_connect($dbhost, $dbuser, $dbpass, $dbname);

// Check the connection
if (!$conn) {
    die("Connection failed: " . mysqli_connect_error());
}

// Fetch all tables in the database
$tables = [];
$result = mysqli_query($conn, "SHOW TABLES");
while ($row = mysqli_fetch_row($result)) {
    $tables[] = $row[0];
}

// Backup each table
$backup_data = "";
foreach ($tables as $table) {
    $result = mysqli_query($conn, "SELECT * FROM {$table}");
    $num_fields = mysqli_num_fields($result);

    $backup_data .= "DROP TABLE IF EXISTS {$table};";
    $create_table_result = mysqli_fetch_row(mysqli_query($conn, "SHOW CREATE TABLE {$table}"));
    $backup_data .= "\n\n" . $create_table_result[1] . ";\n\n";

    while ($row = mysqli_fetch_row($result)) {
        $backup_data .= "INSERT INTO {$table} VALUES(";
        for ($j = 0; $j < $num_fields; $j++) {
            if (isset($row[$j])) {
                $escaped_value = mysqli_real_escape_string($conn, $row[$j]);
                $backup_data .= '"' . $escaped_value . '"';
            } else {
                $backup_data .= 'NULL';
            }
            if ($j < ($num_fields - 1)) {
                $backup_data .= ',';
            }
        }
        
        $backup_data .= ");\n";
    }
    $backup_data .= "\n\n\n";
}

// Save the backup data to the .sql file
file_put_contents($backup_filename, $backup_data);

// Compress the backup file into a .zip archive
$zip = new ZipArchive();
$zip_filename = $backup_filename . '.zip';
$zip->open($zip_filename, ZipArchive::CREATE);
$zip->addFile($backup_filename, basename($backup_filename));
$zip->close();

// Remove the original .sql file
unlink($backup_filename);

// Get the file size of the .zip file
$filesize = filesize($zip_filename);

// Write to the backup.log file with the status and file size of the backup
$log_message = "Backup completed successfully on {$date}. File: " . basename($zip_filename) . ". File size: {$filesize} bytes.\n";
$log_file = $backup_folder . '/backup.log';
file_put_contents($log_file, $log_message, FILE_APPEND);

// Check if the backup folder contains more than 30 backups
$backup_files = glob($backup_folder . '/*.zip');
if (count($backup_files) > 30) {
    // Sort files by creation date
    usort($backup_files, function ($a, $b) {
        return filemtime($a) - filemtime($b);
    });

    // Delete the oldest backup
    unlink($backup_files[0]);
}

// Close the database connection
mysqli_close($conn);

echo $log_message; 
?>