osCommerce中insert or Update 的 function

//抽象用於insert or Update 的 function

// $data 是存入的數據數組

function tep_db_perform($table, $data, $action = 'insert', $parameters = '', $link = 'db_link') {
    reset($data);
    
    if ($action == 'insert') {
      $query = 'insert into ' . $table . ' (';
      while (list($columns, ) = each($data)) {
        $query .= $columns . ', ';
      }
      $query = substr($query, 0, -2) . ') values (';
      reset($data);
      while (list(, $value) = each($data)) {
        switch ((string)$value) {
          case 'now()':
            $query .= 'now(), ';
            break;
          case 'null':
            $query .= 'null, ';
            break;
          default:
            $query .= '\'' . tep_db_input($value) . '\', ';
            break;
        }
      }
      $query = substr($query, 0, -2) . ')';
    }

    elseif ($action == 'update') {
      $query = 'update ' . $table . ' set ';
      while (list($columns, $value) = each($data)) {
        switch ((string)$value) {
          case 'now()':
            $query .= $columns . ' = now(), ';
            break;
          case 'null':
            $query .= $columns .= ' = null, ';
            break;
          default:
            $query .= $columns . ' = \'' . tep_db_input($value) . '\', ';
            break;
        }
      }
      $query = substr($query, 0, -2) . ' where ' . $parameters;
    }

    return tep_db_query($query, $link);
}