Now it's time to save the values entered into database. I will use here previously created method to move data from reference structure to BAPI tables, then I will read values from database to see if something has changed with BAPI_OBJCL_GETDETAIL, then save the values with BAPI_OBJCL_CHANGE. Just one remark, you have to pass all values always to that FM!
 
Importing:

I_DATA TYPE DATA OPTIONAL
value( I_CHANGE_NUMBER ) TYPE BAPI1003_KEY-CHANGENUMBER OPTIONAL -> Change Number 

Exception:

NO_DATA  

Implementation:

method save_charact_from_ref_data.
    field-symbols:
                   <char> type bapi1003_alloc_values_char,
                   <curr> type bapi1003_alloc_values_curr,
                   <num>  type  bapi1003_alloc_values_num,
                   <charnew> type bapi1003_alloc_values_char,
                   <currnew> type bapi1003_alloc_values_curr,
                   <numnew>  type  bapi1003_alloc_values_num.
    dataf_objectkey type bapi1003_key-object.
    dataf_objecttable type bapi1003_key-objecttable.
    dataf_classnum type bapi1003_key-classnum.
    dataf_classtype type bapi1003_key-classtype.
    dataf_different type c.
    dataft_allocvaluesnum type standard table of  bapi1003_alloc_values_num.
    dataft_allocvalueschar type standard table of bapi1003_alloc_values_char.
    dataft_allocvaluescurr type standard table of bapi1003_alloc_values_curr.
    dataft_allocvaluesnumnew type standard table of  bapi1003_alloc_values_num.
    dataft_allocvaluescharnew type standard table of bapi1003_alloc_values_char.
    dataft_allocvaluescurrnew type standard table of bapi1003_alloc_values_curr.
    dataft_return type standard table of bapiret2.


    check i_data is not initial .

    zcl_abapblog_com_classific=>move_ref_data_to_bapi_tables(
      exporting
        i_data           i_data
      
changing
        ct_objvaluesnum  ft_allocvaluesnumnew
        ct_objvalueschar 
ft_allocvaluescharnew
        ct_objvaluescurr 
ft_allocvaluescurrnew
    
exceptions
      no_data_to_pass  1
      others           2
        ).
    if sy-subrc <> 0.
      raise no_data.
    endif.

    call function 'BAPI_OBJCL_GETDETAIL'
      exporting
        objectkey              f_objectkey
        objecttable            
f_objecttable
        classnum               
f_classnum
        classtype              
f_classtype
*   KEYDATE                = SY-DATUM
*   UNVALUATED_CHARS       = ' '
*   LANGUAGE               = SY-LANGU
* IMPORTING
*   STATUS                 = STATUS
*   STANDARDCLASS          = STANDARDCLASS
      tables
        allocvaluesnum         ft_allocvaluesnum
        allocvalueschar        
ft_allocvalueschar
        allocvaluescurr        
ft_allocvaluescurr
        
return                 ft_return
              
.

    "compare old and current entries
    sort ft_allocvalueschar by charact value_neutral.
    sort ft_allocvaluescharnew by charact value_neutral.
    sort ft_allocvaluesnum by charact value_from value_to value_relation  unit_from unit_to.
    sort ft_allocvaluesnumnew by charact value_from value_to value_relation  unit_from unit_to.
    sort ft_allocvaluescurr by charact value_from value_to value_relation currency_from currency_to.
    sort ft_allocvaluescurrnew by charact value_from value_to value_relation currency_from currency_to.

    loop at ft_allocvalueschar assigning <char>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvaluescharnew  with key charact <char>-charact
                                                                    value_neutral 
<char>-value_neutral
                                                                    
transporting no fields
                                                                    binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    loop at ft_allocvaluescharnew assigning <char>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvalueschar  with key charact <char>-charact
                                                 value_neutral 
<char>-value_neutral
                                                  
transporting no fields
                                                  binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    loop at ft_allocvaluesnum assigning <num>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvaluesnumnew  with key charact <num>-charact
                                                value_from 
<num>-value_from
                                                value_to 
<num>-value_to
                                                value_relation 
<num>-value_relation
                                                unit_from 
<num>-unit_from
                                                unit_to 
<num>-unit_to
                                                
transporting no fields
                                                binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    loop at ft_allocvaluesnumnew assigning <num>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvaluesnum  with key charact <num>-charact
                                            value_from 
<num>-value_from
                                            value_to 
<num>-value_to
                                            value_relation 
<num>-value_relation
                                            unit_from 
<num>-unit_from
                                            unit_to 
<num>-unit_to
                                            
transporting no fields
                                            binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    loop at ft_allocvaluescurr assigning <curr>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvaluescurrnew  with key charact <curr>-charact
                                                  value_from 
<curr>-value_from
                                                  value_to 
<curr>-value_to
                                                  value_relation 
<curr>-value_relation
                                                  currency_from 
<curr>-currency_from
                                                  currency_to 
<curr>-currency_to
                                                  
transporting no fields
                                                  binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    loop at ft_allocvaluescurrnew assigning <curr>.
      if f_different is not initial.
        exit.
      endif.
      read table ft_allocvaluescurr  with key charact <curr>-charact
                                              value_from 
<curr>-value_from
                                              value_to 
<curr>-value_to
                                              value_relation 
<curr>-value_relation
                                              currency_from 
<curr>-currency_from
                                              currency_to 
<curr>-currency_to
                                              
transporting no fields
                                              binary search.
      if sy-subrc ne 0.
        f_different 'X'.
      endif.
    endloop.

    check f_different is not initial.

    call function 'BAPI_OBJCL_CHANGE'
      exporting
        objectkey                f_objectkey
        objecttable              
f_objecttable
        classnum                 
f_classnum
        classtype                
f_classtype
*   STATUS                   = '1'
*   STANDARDCLASS            = STANDARDCLASS
       changenumber             i_change_number
*   KEYDATE                  = SY-DATUM
*   NO_DEFAULT_VALUES        = ' '
* IMPORTING
*   CLASSIF_STATUS           = CLASSIF_STATUS
      tables
        allocvaluesnumnew        ft_allocvaluesnumnew
        allocvaluescharnew       
ft_allocvaluescharnew
        allocvaluescurrnew       
ft_allocvaluescurrnew
        
return                   ft_return
              
.


  endmethod.                    "save_charact_from_ref_data