Question

I have the following sql tables

oitems table

    +---------+-----------+----------+
    | orderid | catalogid | numitems |
    +---------+-----------+----------+
    | O737    |       353 |        1 |
    | O738    |       364 |        4 |
    | O739    |       353 |        3 |
    | O740    |       364 |        6 |
    | O741    |       882 |        2 |
    | O742    |       224 |        5 |
    | O743    |       224 |        2 |
    +---------+-----------+----------+

Orders table
+-----------------+------------+------------+
|         orderid | ocardtype  |   odate    |
+-----------------+------------+------------+
|     O737        | Paypal     |            | 'OK
|     O738        | MasterCard | 01.02.2012 | 'OK
|     O739        | MasterCard | 02.02.2012 | 'OK
|     O740        | Visa       | 03.02.2012 | 'OK
|     O741        | Sofort     |            | 'OK
|     O742        |            |            | 'ignore because ocardtype is empty
|     O743        | MasterCard |            | 'ignore because Mastercard no odate
+-----------------+------------+------------+

the reusltant datatable called result

 +-----------+----------+--------------+
| catalogid | numitems | ignoreditems |
+-----------+----------+--------------+
|       353 |        4 |            0 |
|       364 |       10 |            0 |
|       882 |        2 |            0 |
|       224 |        0 |            7 |
+-----------+----------+--------------+

idea is to sum the numitems column for products that have the same catalogid depinding on the data in the oitems table with the following conditions

1. if ocardtype is empty then ignore the numitems and consider it
   as 0 in the sum and sum the ignored items to the ignoreditems
   column
2. if ocardtype for some order is MasterCard or Visa and
   the odate is empty then ignore the numitems and consider it as
   0 and sum the ignored items to the ignoreditems column
3. if ocardtype is Paypal or Sofort, then just do the numitems
   sum
   without checking the date because those types require no odate

basicly i want to save the result datatable to a temporary datatable and load it to a vb.net datatable

i am having a hard time figuring out how to do this in an sql query! i need this as sql command for vb.net , was able to do it programmatically using vb.net datatables using loops and alot of checking
using linq is an option, but i just need to get this from the server

Answer 1

select catalogid, numitems, allitems - numitems ignoreditems
from (
  select i.catalogid,
    sum(case when (ocardtype in ('PayPal','Sofort') OR
                   ocardtype in ('mastercard','visa') and
                   odate is not null) AND NOT EXISTS (
                     select * from booked b
                     where b.ignoredoid = o.orderid
                   ) then numitems
                   else 0 end) numitems,
    sum(numitems) allitems
  from orders o
  join oitems i on i.orderid=o.orderid
  group by i.catalogid
) X