========
this next insert SHOULD FAIL (duplicate primary key):
insert into inventory
*
ERROR at line 1:
ORA-00001: unique constraint (ST10.INVENTORY_PK) violated 


========
Test 1: Inserting a fillable order
========

========
Contents of INVENTORY before Test 1

  ITEM_NUM ITEM_NAME       ITEM_QUANTITY ITEM_PRICE                             
---------- --------------- ------------- ----------                             
         1 widget                    100       1.11                             
         2 gadget                    200       2.22                             
         3 whatsit                   300       3.33                             
         4 doohickey                 400       4.44                             

========
Contents of ORDERS before Test 1:

no rows selected

========
customer HUGHES tries to order 10 of item_num 1 (order number 100)
YAY IT WORKED!!                                                                 

1 row created.

========
in Orders, is there now an Order 100?

ORD CUST_NAME              ITEM_NUM ORDER_QUANTITY                              
--- -------------------- ---------- --------------                              
100 Hughes                        1             10                              

========
in Inventory, are there now 90 of item 1?

  ITEM_NUM ITEM_NAME       ITEM_QUANTITY ITEM_PRICE                             
---------- --------------- ------------- ----------                             
         1 widget                     90       1.11                             
         2 gadget                    200       2.22                             
         3 whatsit                   300       3.33                             
         4 doohickey                 400       4.44                             

========
Test 2: See if an insert of a too-big order FAILS
========

========
TEST 2 --- TRY to order 91 of item_num 1 (order number 200)
insert into orders
            *
ERROR at line 1:
ORA-20601: Order number 200 cannot be placed, because order quantity: 91 is 
more than the stock on hand of 90 
ORA-06512: at "ST10.QUANTITY_CK", line 40 
ORA-04088: error during execution of trigger 'ST10.QUANTITY_CK' 


========
there should be NO order 200 here:

ORD CUST_NAME              ITEM_NUM ORDER_QUANTITY                              
--- -------------------- ---------- --------------                              
100 Hughes                        1             10                              

========
there should STILL be 90 of item 1:

  ITEM_NUM ITEM_NAME       ITEM_QUANTITY ITEM_PRICE                             
---------- --------------- ------------- ----------                             
         1 widget                     90       1.11                             
         2 gadget                    200       2.22                             
         3 whatsit                   300       3.33                             
         4 doohickey                 400       4.44                             

========
Test 3: Will an order for ALL of an item succeed?
========

========
TEST 3 --- TRY to order 200 of item_num 2 (order number 300)
YAY IT WORKED!!                                                                 

1 row created.

========
there should be an order 300 here:

ORD CUST_NAME              ITEM_NUM ORDER_QUANTITY                              
--- -------------------- ---------- --------------                              
100 Hughes                        1             10                              
300 Shmoo                         2            200                              

========
there should be 0 of item 2:

  ITEM_NUM ITEM_NAME       ITEM_QUANTITY ITEM_PRICE                             
---------- --------------- ------------- ----------                             
         1 widget                     90       1.11                             
         2 gadget                      0       2.22                             
         3 whatsit                   300       3.33                             
         4 doohickey                 400       4.44                             

========
Test 4: Will an order for a NEGATIVE number of items succeed?
========
========
TEST 4 --- TRY to order -23 for item_num 4 (order number 400)
does this fail?
insert into orders
            *
ERROR at line 1:
ORA-20600: Order number 400 cannot be placed, because order quantity: -23 must 
be at least 1. 
ORA-06512: at "ST10.QUANTITY_CK", line 23 
ORA-04088: error during execution of trigger 'ST10.QUANTITY_CK' 


========
there should be NO order 400 here:

ORD CUST_NAME              ITEM_NUM ORDER_QUANTITY                              
--- -------------------- ---------- --------------                              
100 Hughes                        1             10                              
300 Shmoo                         2            200                              

========
there should be NO change to quantity of item 4 here:

  ITEM_NUM ITEM_NAME       ITEM_QUANTITY ITEM_PRICE                             
---------- --------------- ------------- ----------                             
         1 widget                     90       1.11                             
         2 gadget                      0       2.22                             
         3 whatsit                   300       3.33                             
         4 doohickey                 400       4.44