Question

I have table with data about tasks like Id, Name, Date, WorkerId, VehicleId (and more 50 fields).

I would like to build orders module that will aloow users insert tasks as an order.
An order contains subset fields from task, for example WorkerId and VehicleId only (as I said – there are more then 50 fields in tasks table).
Since each user can choose his fields definition that compose an order – I have to duplicate the tasks table and name it orders table.
Because the huge size (in terms of fields) of tasks table, I want to avoid duplicate it. Is there any possible way to store order data that not include create huge table like tasks table?

P.S. I don’t want to store the orders in tasks table because:
1. there will be many orders that might affect performance.
2. there are many many tasks already.

Answer 1

It’s hard to tell for sure from your description, but it sounds like you want to treat the columns from the table “tasks” as line items of an order.

ord_num  line_item    task_attribute    attribute_value
--
15       1            WorkerId          35
15       2            VehicleId         101-345-2A3574

Having said that, though, I have to say that

• it does make sense to me to let users
  order tasks, but
• it doesn’t make sense to me to let
  users order one or two columns from a
  table of tasks.

Especially to just order one or two id numbers from a table of tasks–WTF does that mean, anyway?