In the beginning I consider it is very easy to delete attachments via code, just like below.

I have defined one method with following two importing parameters and one returning parameter:

(1) iv_bor_type type string – the BOR type of your business object

(2) iv_uuid type raw16 – the guid of your business object instance

(3) rv_successful type abap_bool – indicates whether the deletion is successful

DATA:     ls_bo          TYPE SIBFLPORB,

         lt_loios    TYPE SKWF_IOS,

         ls_loios    TYPE SKWF_IO,

         ls_error    TYPE SKWF_ERROR,

         lt_badios   TYPE SKWF_IOERRS,

         lv_del_flag TYPE ABAP_BOOL.

   ls_bo-instid = iv_uuid.

   ls_bo-typeid = iv_bor_type.

   ls_bo-catid  = 'BO'.

   rv_successful = abap_false.

   CALL METHOD cl_crm_documents=>get_info

     EXPORTING

       business_object = ls_bo

     IMPORTING

       loios           = lt_loios.

   LOOP AT lt_loios INTO ls_loios.

     CALL METHOD cl_crm_documents=>lock

       EXPORTING

         is_bo    = ls_bo

         is_loio  = ls_loios

       IMPORTING

         es_error = ls_error.

     IF ls_error IS NOT INITIAL.

        RETURN.

     ENDIF.

   ENDLOOP.

   CALL METHOD cl_crm_documents=>delete

     EXPORTING

        business_object = ls_bo

        ios             = lt_loios

     IMPORTING

        bad_ios         = lt_badios

        error           = ls_error.

   IF ls_error IS INITIAL. " deletion failed

      rv_successful = abap_true.

   ENDIF.

Through testing I found it works perfectly well with most of BOR type like product, IBASE, BP, and one order.

However, it does not work for my new BOR type CRMSOCPOST in CRM7.0 EHP3 – the relationship between my BO and the attachments is not really deleted until an explicit call COMMIT WORK is written in the report. However, for any other standard CRM BOR type, the COMMIT WORK is not needed. Why?

After some debugging finally I find answer. Have you already observed the comments below? It is written quite clearly: if the business object exists in the database, the COMMIT WORK is not needed.