Kindly let me the Know Step by Step Procedure of Table Exits. & Field Exits

Question

Dear Members,
   Kindly let me the Know Step by Step Procedure of Table Exits. & Field Exits.
it would be better if u explain by Example....
Hoping for your Response...
Thanks & Warm Regards,
Nitin Chandrawanshi

Answer 1

Some examples:
1.     Extending Business Content - EXIT_SAPLRSAP_001
data: l_s_icctrcst like icctrcst,                                          
         l_s_icctract like icctract,                                          
         l_s_icctrsta like icctrsta,                                          
         l_tabix      like sy-tabix.                                                                               
case i_isource.                                                                               
when '0CO_OM_CCA_1'.                                                     
       loop at c_t_data into l_s_icctrcst.                                    
         l_tabix = sy-tabix.                                                  
         select single * from z0001 where kokrs = l_s_icctrcst-kokrs          
                                    and   kostl = l_s_icctrcst-kostl.         
         if sy-subrc = 0.                                                     
           l_s_icctrcst-zfield1 = z0001-zfield1.                              
           l_s_icctrcst-zfield2 = z0001-zfield2.                              
           modify c_t_data from l_s_icctrcst index l_tabix.                   
         endif.                                                               
       endloop.                                                                               
when '0CO_OM_CCA_2'.                                                     
     when '0CO_OM_CCA_3'.                                                     
     when others.                                                             
       exit.                                                                               
endcase.                                                                 
2.     User Exit after Data loading
(a)     Delete old request
REPORT Z_RSSM_START_SECOND_PROCESS_1 .
TABLES: RSREQDONE,   " Request-Data
        RSSELDONE,   " Selection for current Request
        RSICCONT.    " Request posted to which InfoCube
DATA: L_T_SELDONE LIKE RSSELDONE OCCURS 0 WITH HEADER LINE.
DATA: L_T_ICUBE LIKE RSICCONT OCCURS 0 WITH HEADER LINE.
DATA: L_LOGSYS LIKE RSSELDONE-LOGSYS.
DATA: L_SOURCE LIKE RSSELDONE-SOURCE.
DATA: L_SELDATE LIKE RSSELDONE-SELDATE.
DATA: L_SELTIME LIKE RSSELDONE-SELTIME.
DATA: BEGIN OF L_T_RNR_DEL OCCURS 0,
        ICUBE LIKE RSICCONT-ICUBE,
        RNR   LIKE RSSELDONE-RNR,
      END OF L_T_RNR_DEL.
PARAMETER I_RNR LIKE RSREQDONE-RNR.
SELECT SINGLE * FROM RSSELDONE WHERE
       RNR = I_RNR.
IF SY-SUBRC <> 0. "new rquest does not exist, wrong rnr !!!
  EXIT.
ENDIF.
SELECT * FROM RSICCONT INTO TABLE L_T_ICUBE WHERE
       RNR = I_RNR.
IF SY-SUBRC <> 0.     "New request is not posted to any IC
  EXIT.               "nothing will be deleted
ENDIF.
L_SOURCE  = RSSELDONE-SOURCE.
L_LOGSYS  = RSSELDONE-LOGSYS.
L_SELDATE = RSSELDONE-SELDATE.
L_SELTIME = RSSELDONE-SELTIME.
SELECT * FROM RSSELDONE INTO TABLE L_T_SELDONE WHERE
       SOURCE  = L_SOURCE AND
       LOGSYS  = L_LOGSYS.
DELETE L_T_SELDONE WHERE
       RNR = I_RNR.            "new request will be deleted
DELETE L_T_SELDONE WHERE     "delete younger requests
         SELDATE > L_SELDATE OR
       ( SELTIME > L_SELTIME AND
         SELDATE = L_SELDATE ).
*Sort
SORT L_T_SELDONE BY SELDATE DESCENDING SELTIME DESCENDING.
REFRESH L_T_RNR_DEL.
LOOP AT L_T_SELDONE.   " Requests to be deleted
  LOOP AT L_T_ICUBE.   " Request existing in InfoCubes
    SELECT SINGLE * FROM RSICCONT WHERE
           ICUBE = L_T_ICUBE-ICUBE AND
           RNR   = L_T_SELDONE-RNR.            "check if posted to IC's
    IF SY-SUBRC = 0.
      L_T_RNR_DEL-ICUBE = L_T_ICUBE-ICUBE.
      L_T_RNR_DEL-RNR   = L_T_SELDONE-RNR.
      APPEND L_T_RNR_DEL.
    ENDIF.
  ENDLOOP.
  IF NOT L_T_RNR_DEL[] IS INITIAL. " something found for rnr
    EXIT.
  ENDIF.
ENDLOOP.
LOOP AT L_T_RNR_DEL.
  CALL FUNCTION 'RSSM_DELETE_REQUEST'
       EXPORTING
            REQUEST                    = L_T_RNR_DEL-RNR
            INFOCUBE                   = L_T_RNR_DEL-ICUBE
       EXCEPTIONS
            REQUEST_NOT_IN_CUBE        = 1
            INFOCUBE_NOT_FOUND         = 2
            REQUEST_ALREADY_AGGREGATED = 3
            REQUEST_ALREADY_COMDENSED  = 4
            OTHERS                     = 5.
  IF SY-SUBRC <> 0.
open for error-handling
  ENDIF.
ENDLOOP.
if it helpful reward point are appreciated