Selecting from a comm delimited list

Question

Often we run queries like
SELECT * FROM TABLENAME WHERE FIELDA NOT IN ('A','B','C');
But what if your question goes in the opposite direction, what syntax would work?
In other words. suppose I want to know which values in the list are not in the table. How could I find that out without having to create a temp table?
I'm thinking that something like the following might work:
SELECT FIELDA FROM ('A','B','C') A
WHERE NOT EXISTS (SELECT 1 FROM TABLENAME B
WHERE B.FIELDA = A.FIELDA)

Answer 1

If you have a list of 30,000 items that you want to consider, then you'll likely want to have those items in a table. Here I'll create a fake table of orders, then create a shipment for most of those orders. Then I'll ask which orders of order type "PACKAGE BODY" have not been shipped.
SQL> create table orders as
  2  select object_id AS order_id,
  3         object_type as order_type,
  4         owner as customer
  5    from all_objects;
Table created.
SQL>
SQL> create table shipments as
  2  select *
  3    from orders
  4   where mod(order_id,47) > 0;
Table created.
SQL>
SQL> select order_id
  2    from orders
  3   where order_type = 'PACKAGE BODY'
  4  minus
  5  select order_id
  6    from shipments
  7   where order_type = 'PACKAGE BODY';
  ORDER_ID
      3290
      3619
      3948
      4888
      5499
      5546
     25098
     25192
     29422
     32618
10 rows selected.
SQL>