$host = '127.0.0.1';
$port = 3306;
$dbname = 'test';
$username = 'root';
$password = '';
function ee($p)
{
  if(PHP_SAPI == 'cli')
  {
    echo "\n";
  }else{
    echo "<pre>";
  }
  print_r($p);
  if(PHP_SAPI == 'cli')
  {
    echo "\n";
  }else{
    echo "<pre>";
  }
}
$dsn = "mysql:host={$host};port={$port};dbname={$dbname}";
$opts = array(PDO::ATTR_ERRMODE=>PDO::ERRMODE_EXCEPTION, PDO::ATTR_AUTOCOMMIT=>0);
try {
  $pdo = new PDO($dsn, $username, $password, $opts);
}catch(PDOException $e){
  echo $e->getMessage();
}
//有查询结果
function query($sql)
{
  global $pdo;
  $stmt = $pdo->query($sql);
  $data = $stmt->fetchAll(Pdo::FETCH_BOTH);
  return $data;
}
//无查询结果
function execute($sql)
{
  global $pdo;
  $affect_rows = $pdo->query($sql);
  return $affect_rows;//影响条数
}
$tables = query("show tables");
$sort_data = array();
foreach($tables as $table)
{
  //表记录条数
  $count_sql = "select count(*) as num from {$table[0]}";
  $stmt = $pdo->query($count_sql);
  $info = $stmt->fetch(Pdo::FETCH_BOTH);
  $pad_table = str_pad($table[0], 25, ' ');
  $sort_data[] = array('table'=>$pad_table, 'num'=>$info['num']);
  $sort_index[] = $info['num'];
}
array_multisort($sort_index, SORT_DESC, $sort_data);
foreach($sort_data as $val)
{
  $row_str = <<<eof
 {$val['table']} [{$val['num']}]
eof;
 ee($row_str);
}