Hi,
Please go through this example:
"Example :
REPORT demo_inheritance.
CLASS counter DEFINITION.
PUBLIC SECTION.
METHODS: set IMPORTING value(set_value) TYPE i,
increment,
get EXPORTING value(get_value) TYPE i.
PROTECTED SECTION .
DATA count TYPE i.
ENDCLASS.
CLASS counter IMPLEMENTATION.
METHOD set.
count = set_value.
ENDMETHOD.
METHOD increment.
ADD 1 TO count.
ENDMETHOD.
METHOD get.
get_value = count.
ENDMETHOD.
ENDCLASS.
CLASS counter_ten DEFINITION INHERITING FROM counter.
PUBLIC SECTION.
METHODS increment REDEFINITION .
DATA count_ten.
ENDCLASS.
CLASS counter_ten IMPLEMENTATION.
METHOD increment.
DATA modulo TYPE I.
CALL METHOD super->increment .
write / count.
modulo = count mod 10.
IF modulo = 0.
count_ten = count_ten + 1.
write count_ten.
ENDIF.
ENDMETHOD.
ENDCLASS.
DATA: count TYPE REF TO counter,
number TYPE i VALUE 5.
START-OF-SELECTION.
CREATE OBJECT count TYPE counter_ten .
CALL METHOD count->set EXPORTING set_value = number.
DO 20 TIMES.
CALL METHOD count->increment.
ENDDO.
persistance class
There is a way to avoid building a fully object-oriented program while still working with non-object-oriented relational database. The object services layer now provides a persistence framework that closes the object-relational gap.
You no longer need to write SQL code as objects are transparently loaded from the database when needed. You must create a persistent class. Choose transaction SE24 and create a persistent class; this class must be protected.
steps :
Go to se 24 - choose persistence class
it will be always protected class.
next screen will give u the persistence button when u click on that it will ask u to
add the table or struture.
now u can see two division of the screen where bottom portion of the screen will list uall the fields available and u need to double click and map to the top portion.
Save the persistence class and hit back button..
Whenever u create persistence class zcl_example_persist - it will create two classes - zca_example_persist
and zcb_example_persist automatically
Where zca_example_persist is the agent class and zcb_example_persist is base agent class..
Save and activate.
Activate the whole class. Now that we have a persistent object to access the database table SFLIGHT, we must access it in a program. Here is a small example to read/write data into SFLIGHT using persistent objects.
REPORT ZPERSISTENCECLASS.
data : l_flight type ref to zcl_persist.
data : l_flight_agent type ref to zca_persist.
data : l_seatsfree type i.
data : l_seatsocc type i.
l_flight_agent = zca_persist=>agent.
CATCH CX_OS_OBJECT_NOT_FOUND .
*ENDTRY.
*TRY.
CALL METHOD L_FLIGHT_AGENT->GET_PERSISTENT
EXPORTING
I_CARRID = 'LH'
I_CONNID = '0400'
I_FLDATE = '20060701'
RECEIVING
RESULT = l_flight
.
CATCH CX_OS_OBJECT_NOT_FOUND .
*ENDTRY.
l_seatsfree = L_FLIGHT->GET_SEATSMAX( ) - L_FLIGHT->GET_SEATSOCC( ).
if l_seatsfree > 0.
l_seatsfree = L_FLIGHT->GET_SEATSOCC( ) + 1.
l_flight->set_seatsocc( l_seatsfree ).
endif.
Reward Points if found helpfull..
Cheers,
Chandra Sekhar.
Bluesky
