ABAP - Data Change Tracker for Custom Tables

Applies to:
SAP ECC 6.0

Summary
In SAP implementation for a business, not all the requirements are covered in the standard SAP tables. There are possibilities wherein custom tables are used to hold important data.

This tutorial will explain on tracking data changes in custom tables through standard SAP change tables.

Author: Booma Ganesan
Company: Infosys Technologies Limited
Created on: 18 September 2009
Author Bio
Booma Ganesan is working as an ABAP consultant in Infosys Technologies Limited,chennai. She has completed Bachelor of Technology in Information Technology.

Table of Contents

Scope

Based on the customeer needs, custom tables are used to to hold important data and hence making it necessary to track the changes madeto them.

Standard change tables CDHR and CDPOS are used for tracking the changes made to the standard SAP objects.This tutorial will explain the procedure to track the changes made to custom tables and logging those changes in standard SAP change tables.

Two major processes involved in tracking the changes of custom tables are -

Change document object
Function module for the change document object

Illustration

Let us take an example of using a custom table to hold employee details with their email ids.

Pre-requisite

To support the tracking process we need to enable the check box for 'change document' in the respective data elements for all those which needs to be tracked.

The sample screen shot is as shown below.

Step by step explanation on creation of change document object

1. Go to Transaction code SCDO. Click on 'Create' button to start the creation of change document object.

2. Enter the name of the change document object in the pop-up screen. In our example the change document object class name is 'YTEST_TABLE_CNG".

Click the continue button. A pop-up screen to confirm the activity is displayed. Press yes to confirm in the confirmation screen. In the next screen, specify the package and TR details as required.

3. Specify the text for change document object and the table name, for which the change document object is been created. Press enter to continue.

4. Click on the menu 'Utilities (M)' and select 'Generate Update Program'. Press yes in the pop-up screen and continue.

5. A new screen will be displayed, wherein we need to specify the function group name.

Press yes to confirm the generation of the function group for the change document object.

6. All the details like the function group, function module and include names are listed before generation. Press "SAVE" to complete the program generation for the change document object.

Note: The change document object will be saved in a workbench request and it follows the regular TR migration procedure.

Now change document object for the custom table is created. Function module created through the program generation needs to be used for logging the changes in the standard SAP change tables - CDHDR and CDPOS. The operations like Insert, Update and Delete functionalities can be done on the entries available in the custom table.

For performing all the function, we need to add variable of type CHAR1 in the import parameters of the function module. When the value is passed as 'X' and the operation to be performed is 'D' (delete), then the current record is logged for deletion in CDHDR.

All the changes to the data available in the custom tables can be tracked with the change document object.

Using change document object's Function Module

To have more clarity on the tracking procedure, I have explained the usage of the function module through a report program. Before running the report program, our custom table is maintained with few entries to enable the update operation.

The report program will take the empno and type of operations to be performed from the selection screen and execute the set of codes accordingly.

Initially no details are availble against our change object class in both CDHDR and CDPOS table.

Update Functionality

Now the report program is executed with the below inputs
EMP no: 1001
Operation to be performed: update

* fetch all the details from the Ztable
 SELECT SINGLE * FROM ytest_table
       INTO gs_test
       WHERE zemp_no = p_emp_no.
 IF sy-subrc = 0.
 * move the old entries
   CLEAR ls_test.
   ls_test = gs_test.
 * New Values
   gs_test-zemp_no = p_emp_no.
   gs_test-zename = 'new_name1'.
   gs_test-zmail_id = Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo.'.
   gs_test-zcontact_no = '02211336655'.
   APPEND gs_test TO gt_test.
 *Populate change tables
   CLEAR gs_change.
   gs_change-teilobjid = 'YTEST_TABLE_CNG'.
   gs_change-textart = 'TEST_2'.
   gs_change-textspr = 'EN'.
   gs_change-updkz = 'U'.
   APPEND gs_change TO gt_change.
 *Call the FM to log the values in CDHDR table.
   CALL FUNCTION 'YTEST_TABLE_CNG_WRITE_DOCUMENT'
     EXPORTING
       objectid                   = 'YTEST_TABLE_CNG'
       tcode                      = sy-tcode
       utime                      = sy-uzeit
       udate                      = sy-datum
       username                   = sy-uname
       planned_change_number      = ' '
       object_change_indicator    = 'U'
       planned_or_real_changes    = 'U'
       no_change_pointers         = 'U'
       upd_icdtxt_ytest_table_cng = 'U'
       n_ytest_table              = gs_test
       o_ytest_table              = ls_test
       upd_ytest_table            = 'U'
       lv_opt                     = ' '
     TABLES
       icdtxt_ytest_table_cng     = gt_change.

After execution the CDHDR table is logged with one entry for our change object

Corresponding CDPOS values

Likewise all the other modified fields are logged in CDPOS table.
Modified values reflecting in custome tables using update statement.

Insert functionality

The report program is executed for insert functionality with the below inputs

CLEAR: GS_TEST,
LS_TEST.
GS_TEST-ZEMP_NO = P_EMP_NO.
GS_TEST-ZENAME = 'name_ins'.
GS_TEST-ZMAIL_ID = Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo.'.
GS_TEST-ZCONTACT_NO = '1112131415'.
APPEND GS_TEST TO GT_TEST.

*populate change table
CLEAR GS_CHANGE.
GS_CHANGE-TEILOBJID = 'YTEST_TABLE_CNG'.
GS_CHANGE-TEXTART = 'TEST_1'.
GS_CHANGE-TEXTSPR = 'EN'.
GS_CHANGE-UPDKZ = 'I'.
APPEND GS_CHANGE TO GT_CHANGE.

*call the fM to log the values in CDHDR table.
CALL FUNCTION 'YTEST_TABLE_CNG_WRITE_DOCUMENT'
EXPORTING
OBJECTID = 'YTEST_TABLE_CNG'
TCODE = SY-TCODE
UTIME = SY-UZEIT
UDATE = SY-DATUM
USERNAME = SY-UNAME
PLANNED_CHANGE_NUMBER = ' '
OBJECT_CHANGE_INDICATOR = 'I'
PLANNED_OR_REAL_CHANGES = 'I'
NO_CHANGE_POINTERS = 'I'
UPD_ICDTXT_YTEST_TABLE_CNG = 'I'
N_YTEST_TABLE = GS_TEST
O_YTEST_TABLE = LS_TEST
UPD_YTEST_TABLE = 'I'
LV_OPT = ' '
TABLES
ICDTXT_YTEST_TABLE_CNG = GT_CHANGE.

The details logged in CDHDR and CDPOS are as below.

Corresponding entries in CDPOS

The new entry is added to the custom table using insert statement.

Delete Functionality

The report program is executed for delete functionality with the below inputs

* fetch all the details from the ztable.
SELECT SINGLE * FROM YTEST_TABLE
INTO GS_TEST
WHERE ZEMP_NO = P_EMP_NO.

*move the old entries
IF SY-SUBRC = 0.
CLEAR LS_TEST.
LS_TEST = GS_TEST.
CLEAR GS_TEST.

*populate change table
CLEAR GS_CHANGE.
GS_CHANGE-TEILOBJID = 'YTEST_TABLE_CNG'.
GS_CHANGE-TEXTART = 'TEST_3'.
GS_CHANGE-TEXTSPR = 'EN'.
GS_CHANGE-UPDKZ = 'D'.
APPEND GS_CHANGE TO GT_CHANGE.

*call the fM to log the values in CDHDR table.
CALL FUNCTION 'YTEST_TABLE_CNG_WRITE_DOCUMENT'
EXPORTING
OBJECTID = 'YTEST_TABLE_CNG'
TCODE = SY-TCODE
UTIME = SY-UZEIT
UDATE = SY-DATUM
USERNAME = SY-UNAME
PLANNED_CHANGE_NUMBER = ' '
OBJECT_CHANGE_INDICATOR = 'D'
PLANNED_OR_REAL_CHANGES = 'D'
NO_CHANGE_POINTERS = 'D'
UPD_ICDTXT_YTEST_TABLE_CNG = 'D'
N_YTEST_TABLE = GS_TEST
O_YTEST_TABLE = LS_TEST
UPD_YTEST_TABLE = 'D'
LV_OPT = 'X'
TABLES
ICDTXT_YTEST_TABLE_CNG = GT_CHANGE.

Log in CDHDR

Note: In CDPOS, the change ID is logged as 'E' - Delete (Single field documentation). In CDPOS all the changes made to particular row is been logged field wise and hence the change in ID.

The screen shot of the modified values reflecting in the custom table.

Reading Change logs

I have also added a button in application toolbar to list all the details logged in CDHDR And its corresponding entries in CDPOS tables in an alv grid display.

To read the entries from the change tables - CDHDR , CDPOS the below two functiona modules are used.

CHANGEDOCUMENT_READ_HEADERS
CHANGEDOCUMENT_READ_POSITIONS

DATA: LS_CDRED LIKE LINE OF GT_CDRED.

CALL FUNCTION 'CHANGEDOCUMENT_READ_HEADERS'
EXPORTING
ARCHIVE_HANDLE = 0
DATE_OF_CHANGE = '00000000'
OBJECTCLASS = 'YTEST_TABLE_CNG'
OBJECTID = ' '
TIME_OF_CHANGE = '000000'
USERNAME = SY-UNAME
LOCAL_TIME = ' '
DATE_UNTIL = '99991231'
TIME_UNTIL = '235959'
NOPLUS_ASWILDCARD_INOBJID = ' '
TABLES
I_CDHDR = GT_CDHDR
EXCEPTIONS
NO_POSITION_FOUND = 1
WRONG_ACCESS_TO_ARCHIVE = 2
TIME_ZONE_CONVERSION_ERROR = 3
OTHERS = 4.
IF SY-SUBRC <> 0.
MESSAGE 'No entries found' TYPE 'E'.
ENDIF.

IF NOT GT_CDHDR IS INITIAL.

LOOP AT GT_CDHDR INTO GS_CDHDR.

CALL FUNCTION 'CHANGEDOCUMENT_READ_POSITIONS'
EXPORTING
CHANGENUMBER = GS_CDHDR-CHANGENR
TABLES
EDITPOS = GT_CDSHW
EDITPOS_WITH_HEADER = GT_CDRED
EXCEPTIONS
NO_POSITION_FOUND = 1
WRONG_ACCESS_TO_ARCHIVE = 2
OTHERS = 3.
IF SY-SUBRC <> 0.
MESSAGE 'No item details found' TYPE 'E'.
ELSE.
LOOP AT GT_CDRED INTO LS_CDRED.
MOVE-CORRESPONDING GS_CDHDR TO GS_OUT.
MOVE-CORRESPONDING LS_CDRED TO GS_OUT.
APPEND GS_OUT TO GT_OUT.
CLEAR: GS_OUT,
LS_CDRED.
ENDLOOP.
CLEAR: GS_CDHDR.
ENDIF.
ENDLOOP.
ENDIF.

Report Output

* fetch all the details from the Ztable
SELECT SINGLE * FROM ytest_table
      INTO gs_test
      WHERE zemp_no = p_emp_no.
IF sy-subrc = 0.
* move the old entries
  CLEAR ls_test.
  ls_test = gs_test.
* New Values
  gs_test-zemp_no = p_emp_no.
  gs_test-zename = 'new_name1'.
  gs_test-zmail_id = Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo.'.
  gs_test-zcontact_no = '02211336655'.
  APPEND gs_test TO gt_test.
*Populate change tables
  CLEAR gs_change.
  gs_change-teilobjid = 'YTEST_TABLE_CNG'.
  gs_change-textart = 'TEST_2'.
  gs_change-textspr = 'EN'.
  gs_change-updkz = 'U'.
  APPEND gs_change TO gt_change.
*Call the FM to log the values in CDHDR table.
  CALL FUNCTION 'YTEST_TABLE_CNG_WRITE_DOCUMENT'
    EXPORTING
      objectid                   = 'YTEST_TABLE_CNG'
      tcode                      = sy-tcode
      utime                      = sy-uzeit
      udate                      = sy-datum
      username                   = sy-uname
      planned_change_number      = ' '
      object_change_indicator    = 'U'
      planned_or_real_changes    = 'U'
      no_change_pointers         = 'U'
      upd_icdtxt_ytest_table_cng = 'U'
      n_ytest_table              = gs_test
      o_ytest_table              = ls_test
      upd_ytest_table            = 'U'
      lv_opt                     = ' '
    TABLES
      icdtxt_ytest_table_cng     = gt_change.

* fetch all the details from the Ztable

SELECT SINGLE * FROM ytest_table

INTO gs_test

WHERE zemp_no = p_emp_no.

IF sy-subrc = 0.

* move the old entries

CLEAR ls_test.

ls_test = gs_test.

* New Values

gs_test-zemp_no = p_emp_no.

gs_test-zename = 'new_name1'.

gs_test-zmail_id = Esta dirección de correo electrónico está siendo protegida contra los robots de spam. Necesita tener JavaScript habilitado para poder verlo.'.

gs_test-zcontact_no = '02211336655'.

APPEND gs_test TO gt_test.

*Populate change tables

CLEAR gs_change.

gs_change-teilobjid = 'YTEST_TABLE_CNG'.

gs_change-textart = 'TEST_2'.

gs_change-textspr = 'EN'.

gs_change-updkz = 'U'.

APPEND gs_change TO gt_change.

*Call the FM to log the values in CDHDR table.

CALL FUNCTION 'YTEST_TABLE_CNG_WRITE_DOCUMENT'

EXPORTING

objectid = 'YTEST_TABLE_CNG'

tcode = sy-tcode

utime = sy-uzeit

udate = sy-datum

username = sy-uname

planned_change_number = ' '

object_change_indicator = 'U'

planned_or_real_changes = 'U'

no_change_pointers = 'U'

upd_icdtxt_ytest_table_cng = 'U'

n_ytest_table = gs_test

o_ytest_table = ls_test

upd_ytest_table = 'U'

lv_opt = ' '

TABLES

icdtxt_ytest_table_cng = gt_change.

Login

Tracker for custom tables