Selection-screen: is a screen is used to give the value ranges on the selection-screen. It has include the attributes like Sign, Option, Low, and High.
Selection-screen Output: is a screen is used to change the selection-screen dynamically. Like the field enabling, disabling, field Hiding Purpose.
At selection-screen output is triggered when the selection
screen is loaded in memory before being displayed. The
event AT SELECTION-SCREEN is the basic form of a whole
series of events that occur while the selection screen is
being processed.The standard selection screen in an
executable program or in the logical database linked to it
is automatically called between the INITIALIZATION and
START-OF-SELECTION events. When you call the selection
screen, and when users interact with it, the ABAP runtime
environment generates selection screen events, which occur
between INITIALIZATION and START-OF-SELECTION.
At selection-screen : This event mainly used to validate the
user inputs.
At selection-screen output : This event is used for
processing screen . We can enable or disable the screen
blocks and we can make some field active or deactivate at
run time.
at selection screen on output is used to set screen attributes
AT SELECTION_SCREEN OUTPUT
LOOP AT SCREEN.
if VIEW = 'X' " View radio button selects
IF SCREEN-NAME = 'PR1'.
screen-INPUT = 0.
modify screen.
ENDIF.
IF SCREEN-NAME = 'PR2'.
screen-INPUT = 0.
modify screen.
ENDIF.
ENDLOOP.
AT SELECTION-SCREEN.
*val....1 Variant check
* Once the user has entered variant, check about its existence
PERFORM CHECK_PVAR. "Using FM REUSE_ALV_VARIANT_EXISTENCE
*val....2 Sd do not exists
SELECT SINGLE VBELN INTO WA_HEADER-VBELN FROM VBAK WHERE VBELN IN
S_VBELN.
IF SY-SUBRC 0.
MESSAGE E010 WITH TEXT-010.
ENDIF.
*val.....3 Date of creation check
LOOP AT S_DOC.
IF S_DOC-LOW > SY-DATUM OR S_DOC-HIGH > SY-DATUM.
MESSAGE E011 WITH TEXT-011.
ENDIF.
ENDLOOP.
*VAL....4
if P_DOWN = 'X' AND P_PATH is initial.
MESSAGE E011 WITH TEXT-011.
endif.
if P_DW_RP = 'X' AND P_path is initial.
MESSAGE E011 WITH TEXT-011.
endif.
what is Foreign key, check table and value table ....?
what is the difference between CHECK AND VALUE TABLE ..?
PLEASE GIVE THE APPROPRIATE ANSWERS......
BDC CALL TRANSACTION carry on synchronous processing and
update the database both synchronously and
asynchronously,where session method carry on asynchoronous
processing and update the database synchrousnously.I want
to know the meaning of synchronous and asynchronous
processing and also the meaning of synchronous and
asynchronous database update.