DEFINE TEMP-TABLE customers
   field customer_id as INT
   field customer_name as character
   index Idxcustomer_id is unique customer_id
.

DEFINE TEMP-TABLE orders 
   field customer_id as INT
    field order_amount as int
    
.

create customers.
customers.customer_id = 1.
customers.customer_name = 'John Doe'.

create customers.
customers.customer_id = 2.
customers.customer_name = 'John Smith'.

create orders.
orders.customer_id = 1.
orders.order_amount = 10.

create orders.
orders.customer_id = 1.
orders.order_amount = 20.

create orders.
orders.customer_id = 2.
orders.order_amount = 15.


DEFINE VARIABLE qh AS WIDGET-HANDLE.

CREATE QUERY qh.
qh:add-buffer(BUFFER customers:HANDLE).
qh:add-BUFFER(BUFFER orders:HANDLE).
qh:QUERY-PREPARE("FOR EACH customers of orders WHERE orders.customer_id = customers.customer_id").
qh:QUERY-OPEN.
 
REPEAT WITH FRAME y:
    qh:GET-NEXT().
    IF qh:QUERY-OFF-END THEN LEAVE.
    display qh:GET-BUFFER-HANDLE(1):BUFFER-FIELD('customer_id'):BUFFER-VALUE.
    END.

qh:QUERY-CLOSE().
DELETE OBJECT qh.