Hi Guys,
while working with own database tables (Z* tables) the SAP offers us a simple tool to add data or edit these tables. I am talking about the table maintenance views, that you can call via the transaction SM30. The problem is that only one user can edit such a table at once. For my application this was unsatisfying because several users worldwide couldn't consider waiting until one has finished his changings. I sersched the SCN and found serveral threads handling this issue. After implementing it myself i wanted to share my knowledge with you and carry the information together.
So at first you need the database table and you have to generate a table maintenance view. While Generating this View choose two step maintenance type, because we want a list where several entries are not editable. In the overview screen no entry is editable in general, in detail screen it gets editable when opened with changing.
When you enter the table maintenance view via SM30 a table level lock is set. This lock has to be removed. The most easiest way to do that is a report that deletes the lock and calls the maintenance view. In detail this is done by reading all system locks. After that we have to delete the relevant lock by calling the function module ENQUE_DELETE. Now you can call the table maintenance view via the function module VIEW_MAINTENANCE_CALL. It is recommendable to add a transaction to this report because it has to be processed to delete the locks. Otherwise if someone opens table maintenance view via SM30 this will not work any more and the lock is set again.
Code Example:
REPORT ztest.
DATA:
BEGIN OF seltab OCCURS 1.
INCLUDE STRUCTURE vimsellist.
DATA: END OF seltab,
BEGIN OF excl_cua_funct OCCURS 1.
INCLUDE STRUCTURE vimexclfun.
DATA: END OF excl_cua_funct.
DATA: lt_enq_del TYPE STANDARD TABLE OF seqg3,
lt_enq_read TYPE STANDARD TABLE OF seqg7,
lw_enq_read TYPE seqg7,
lw_enq_del TYPE seqg3,
lv_subrc TYPE sy-subrc.
*Read all locks in system
CALL FUNCTION 'ENQUE_READ2'
EXPORTING
gclient = sy-mandt
gname = ' '
guname = '*'
TABLES
enq = lt_enq_read.
*We will search entry for table level lock for our table
LOOP AT lt_enq_read INTO lw_enq_read WHERE gname EQ 'RSTABLE'
AND garg CS 'Z_OURTABLE.
MOVE-CORRESPONDING lw_enq_read TO lw_enq_del.
APPEND lw_enq_del TO lt_enq_del.
- ENDLOOP.
*Delete lock entry for our table
CALL FUNCTION 'ENQUE_DELETE'
EXPORTING
check_upd_requests = 1
IMPORTING
subrc = lv_subrc
TABLES
enq = lt_enq_del.
CALL FUNCTION 'VIEW_MAINTENANCE_CALL'
EXPORTING
action = 'U'
* CORR_NUMBER = ' '
* GENERATE_MAINT_TOOL_IF_MISSING = ' '
* SHOW_SELECTION_POPUP = ' '
view_name = 'Z_OURTABLE'.
Now every entry we are editing has to be locked for other user. To achieve that we need a lock object configured for our table Z_OURTABLE. Everytime we enter the detail screen we check if this entry locked and if so, we set all fields not editable. For that the Screen logic of the dynpro has to be modified. You can add a module that calls the function module created by your locking object. Be careful , if you change your database table, the screens have to be generated new and also the PBO Module has to be added again.
Code example:
MODULE change_locking OUTPUT.
CALL FUNCTION 'ENQUEUE_EZOURTABLELOCKOBJECT
EXPORTING
kunnr = zourtable-kunnr
EXCEPTIONS
foreign_lock = 1
system_failure = 2
OTHERS = 3.
IF sy-subrc <> 0.
message 'Data locked by another user!' type 'S'.
* row is locked..
LOOP AT SCREEN.
screen-input = 0.
MODIFY SCREEN.
ENDLOOP.
ENDIF.
- ENDMODULE.
Everytime a user opens a single record this is locked by the locking object. If any user tries to open the same record all fields are enhanced grey.
I hope this is useful to someone.
kind regards Tobias
