Calculate MySQL database size with PHP (off the old shelf)

All this piece of PHP code needs is your MySQL database credentials to calculate the MySQL database size.

<?php
/**
 * Function to calculate the size, in bytes, of a MySQL database
 * Needs $dbhostname, $db, $dbusername, $dbpassword
 * - Jan Reilink <jan@saotn.nl>, Twitter: @Jan_Reilink
 */
$dbhostname = "hostname";
$db = "database name";
$dbusername = "user name";
$dbpassword = "password";
$link = mysql_connect( $dbhostname,$dbusername,$dbpassword );
if( !$link ) {
  die( mysql_error() );
}
$db_selected = mysql_select_db( $db, $link );
if ( !$db_selected ) {
  die( mysql_error() );
}

function get_dbsize( $db ) {
  $query = "SHOW TABLE STATUS FROM `".$db."`";
  if ( $result = mysql_query( $query ) ) {
    $tables = 0;
    $rows = 0;
    $size = 0;
    while ( $row = mysql_fetch_array( $result,MYSQL_ASSOC ) ) {
      $rows += $row["Rows"];
      $size += $row["Data_length"];
      $size += $row["Index_length"];
      $tables++;
    }
  }
  $data[0] = $size;
  $data[1] = $tables;
  $data[2] = $rows;
  return $data;
}

$result = get_dbsize( $db );
$megabytes = $result[0] / 1024 / 1024;

/* http://www.php.net/manual/en/function.number-format.php */
$megabytes = number_format( round( $megabytes, 3 ), 2, ',', '.' );
?>

For MySQL database size, the array $data[] holds all the information in its keys:

1. 0: size, in bytes
2. 1: number of tables in the database
3. 2: number of rows

Use with caution! And it shouldn't be too difficult to rewrite this to MySQLi.

Calculate the MySQL database size by querying MySQL information_scheme database

You can use the following MySQL query, as a pure MySQL solution, to get the MySQL database size. It queries the information_scheme database:

SELECT SUM( data_length + index_length )
FROM information_schema.tables
WHERE table_schema = '[db-name]';