Check if exist sql command into string

function.php

function existSqlCommand($param){
  $notAllowedCommands = array(
      'DELETE',
      'TRUNCATE',
      'DROP',
      'SELECT',
      'UPDATE'
  );

  if(preg_match('[' . implode(' |', $notAllowedCommands ) . ']i', $param) == true) {
    return true;
  }
  return false;
}