mysqldump is not dumping any table

Question

I can't manage to backup my MySQL database. I use the following command:

mysqldump --user=user --password=password db > db.sql

This is what the output file looks like:

-- MySQL dump 10.11
--
-- Host: localhost    Database: db
-- ------------------------------------------------------
-- Server version   5.0.96-community

/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET @OLD_CHARACTER_SET_RESULTS=@@CHARACTER_SET_RESULTS */;
/*!40101 SET @OLD_COLLATION_CONNECTION=@@COLLATION_CONNECTION */;
/*!40101 SET NAMES utf8 */;
/*!40103 SET @OLD_TIME_ZONE=@@TIME_ZONE */;
/*!40103 SET TIME_ZONE='+00:00' */;
/*!40014 SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
/*!40111 SET @OLD_SQL_NOTES=@@SQL_NOTES, SQL_NOTES=0 */;

That's it. Not any CREATE TABLE and not any INSERT... I also noticed in posts for similar problems that there always was a -- Dump completed on YYYY-MM-DD HH:MM:SS at the end of the output, which is not the case here. My username and my password are correct and the user has all possible privileges.

What am I doing wrong?

Answer 1

Since asking this question, my web host deactivated the shell_exec() command, so now I'm using a PHP script to backup my database. Here's the function I'm using:

function backup_tables($host, $user, $pass, $name, $tables='*', $backup_path) {
    $link = mysql_connect($host,$user,$pass);
    mysql_select_db($name,$link);

    //get all of the tables
    if($tables == '*') {
        $tables = array();
        $result = mysql_query('SHOW TABLES');

        while($row = mysql_fetch_row($result)) {
            $tables[] = $row[0];
        }
    }
    else {
        $tables = is_array($tables) ? $tables : explode(', ',$tables);
    }

    $droptables = 'DROP TABLE IF EXISTS ';

    for ($i = sizeof($tables) - 1; $i >= 0; $i--) {
        $droptables .= '`' . $tables[$i] . '`';
        if ($i > 0) {
            $droptables .= ', ';
        } else {
            $droptables .= ';';
        }
    }

    //cycle through
    foreach($tables as $table) {
        $result = mysql_query('SELECT * FROM '.$table);
        $num_fields = mysql_num_fields($result);

        // $droptables.= '`' . $table . '`, ';
        $row2 = mysql_fetch_row(mysql_query('SHOW CREATE TABLE '.$table));
        $data .= "\n\n".$row2[1].";\n\n";

        for ($i = 0; $i < $num_fields; $i++) {
            while($row = mysql_fetch_row($result)) {
                $data .= 'INSERT INTO '.$table.' VALUES(';

                for ($j = 0; $j < $num_fields; $j++) {
                    if (isset($row[$j])) {
                        $row[$j] = addslashes($row[$j]);
                        $row[$j] = ereg_replace("\n","\\n",$row[$j]);
                        $data .= '"'.$row[$j].'"' ;
                    } else {
                        $data .= 'NULL';
                    }

                    if ($j < ($num_fields-1)) {
                        $data .= ',';
                    }
                }

                $data .= ");\n";
            }
        }

        $data .= "\n\n\n";
    }

    $return = $droptables . $return;

    //save file
    $date = date('Ymd-His');
    $filename = 'db-backup-' . $date . '.sql';
    $handle = fopen($backup_path.$filename,'w+');
    fwrite($handle, utf8_encode($return));
    fclose($handle);

    $gzfile = $filename . '.gz';
    $handle = gzopen($backup_path.$gzfile, 'w9');
    gzwrite($handle, file_get_contents($backup_path.$filename));
    gzclose($handle);
}

Example usage: backup_tables('localhost','user','pass','database', 'users, posts, comments, subscriptions', '/home/user/db_backups/');. You just have to remember to put the tables with foreign keys at the end of the list.