Using the Transaction Script pattern - POJOs in Action: Developing Enterprise Applications with Lightweight Frameworks - page 347

The first SELECT statement is executed when findPendingOrder() calls i BATIS and
retrieves the pending order and its restaurant using an outer join. The other two
statements are automatically executed by the first statement's result map when it
initializes the PendingOrderDTO and RestaurantDTO objects. The second statement
retrieves the line items and their associated menu items. The third statement
retrieves the menu items for the restaurant. Figure 9.7 shows the statements and
result maps that we must write to execute these statements.

select *
from FTGO_PENDING_ORDER_LINE_ITEM l,
FTGO_MENU_ITEM mi
where l.pending_order_id = ?
AND mi.menu_item_id = l.menu_item_id

select *
from
FTGO_PENDING_ORDER o,
FTGO_RESTAURANT r
where o.pending_order_id = ?
AND r.restaurant_id (+)=
o.restaurant_id

<<statement>>
findPendingOrder

PendingOrder
DTO

uses

creates

<<result map>>
PendingOrder
ResultMap

creates

Restaurant
DTO

executes

executes

select *
from FTGO_MENU_ITEM mi
where mi.restaurant_id = ?

<<statement>>
findLineItems

<<statement>>
findMenuItems

uses uses

<<result map>>
PendingOrderLine
ItemResultMap

<<result map>>
MenuItemResult
Map

creates

creates

PendingOrder
LineItem
DTO

MenuItem
DTO

Figure 9.7 Mapped statements and result maps required to load a pending order, its line items,
restaurant, and menu items