ABAP Select data from SAP table RNNLZD into internal table

Get Example source ABAP code based on a different SAP table
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Below is a number of ABAP code snippets to demonstrate how to select data from SAP RNNLZD table and store it within an internal table, including using the newer @DATA inline declaration methods. It also shows you various ways to process this data using ABAP work area, inline declaration or field symbols including executing all the relevant CONVERSION_EXIT routines specific to RNNLZD. See here for more generic Select statement tips.

Sometimes data within SAP is stored within the database table in a different format to what it is displayed to the user. These input/output conversation FM routines are what translates the data between the two formats.

There is also a full declaration of the RNNLZD table where each field has a char/string type for you to simply copy and paste. This allows you to use processing that is only available to these field types such as the CONCATENATE statement.

DATA: IT_RNNLZD TYPE STANDARD TABLE OF RNNLZD,
      WA_RNNLZD TYPE RNNLZD,
      GD_STR TYPE STRING.

DATA: lo_typedescr type REF TO cl_abap_typedescr.
DATA: lv_fieldname type fieldname.

FIELD-SYMBOLS: <FIELD> TYPE any.
FIELD-SYMBOLS: <RNNLZD> TYPE RNNLZD.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_RNNLZD.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM RNNLZD
  INTO TABLE IT_RNNLZD.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM RNNLZD
*  INTO TABLE @DATA(IT_RNNLZD2).
*--Further methods of using ABAP code to  select data from SAP database tables

*You can also declare the header/work area using the in-line DATA declaration method
READ TABLE IT_RNNLZD INDEX 1 INTO DATA(WA_RNNLZD2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_RNNLZD ASSIGNING <RNNLZD>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<RNNLZD>-MANDT = 1.
<RNNLZD>-LNRLS = 1.
<RNNLZD>-ASHOSP = 1.
<RNNLZD>-GPART = 1.
<RNNLZD>-ROLTP = 1.

ENDLOOP.

LOOP AT IT_RNNLZD INTO WA_RNNLZD.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_RNNLZD-ROLBZ, sy-vline,
  WA_RNNLZD-PNAME, sy-vline,
  WA_RNNLZD-EINRI, sy-vline,
  WA_RNNLZD-FALNR, sy-vline,
  WA_RNNLZD-BETRAG, sy-vline,
  WA_RNNLZD-PROZENT, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_RNNLZD you want to display...

  WRITE:/ sy-uline.
* Aternatively use generic code to Write field values (and NAME) to screen report
  DO.
    ASSIGN COMPONENT sy-index OF STRUCTURE wa_RNNLZD TO <field>.
    IF sy-subrc <> 0. EXIT. ENDIF.
    WRITE:/ 'Field Value', <field>, sy-vline.
    gd_str = <field> .
    lo_typedescr ?= CL_ABAP_DATADESCR=>DESCRIBE_BY_DATA( <field> ).
    lv_fieldname = lo_typedescr->GET_RELATIVE_NAME( ).
    WRITE:/ 'Field Name', lv_fieldname.
  ENDDO.

  
*Redo loop but convert all fields from internal to out value  
LOOP AT IT_RNNLZD INTO WA_RNNLZD.


*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Convert all fields to display/output versions using conversion routines
  PERFORM convert_all_field_values CHANGING wa_EKKO.
	 
ENDLOOP.

  
*&---------------------------------------------------------------------*
*& Form convert_all_field_values
*&---------------------------------------------------------------------*
FORM convert_all_field_values CHANGING p_EKKO LIKE wa_EKKO.
DATA: ld_input(1000) TYPE c, ld_output(1000) TYPE C.

*Conversion exit ALPHA, internal->external for field LNRLS
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-LNRLS
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-LNRLS.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field ASHOSP
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-ASHOSP
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-ASHOSP.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field GPART
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-GPART
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-GPART.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field ROLTP
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-ROLTP
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-ROLTP.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field EINRI
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-EINRI
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-EINRI.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field FALNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_RNNLZD-FALNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RNNLZD-FALNR.
WRITE:/ 'New Value:', ld_input.
ENDFORM. 

*&---------------------------------------------------------------------*
*& Form process_as_string_field_values
*&---------------------------------------------------------------------*
FORM process_as_string_field_values CHANGING p_EKKO LIKE wa_EKKO.

TYPES: BEGIN OF T_RNNLZD_STR, 
MANDT TYPE STRING,
LNRLS TYPE STRING,
ASHOSP TYPE STRING,
GPART TYPE STRING,
ROLTP TYPE STRING,
ROLBZ TYPE STRING,
PNAME TYPE STRING,
EINRI TYPE STRING,
FALNR TYPE STRING,
BETRAG TYPE STRING,
PROZENT TYPE STRING,
AEQUI TYPE STRING,
NNLZ TYPE STRING,
MARK TYPE STRING,
MODUS TYPE STRING,END OF T_EKKO_STR.
DATA: WA_RNNLZD_STR type T_EKKO_STR.

DATA: ld_text TYPE string.

LOOP AT IT_EKKO INTO WA_EKKO.
  MOVE-CORRESPONDING wa_EKKO TO WA_EKKO_STR.
  CONCATENATE: sy-vline
WA_RNNLZD_STR-MANDT sy-vline 
WA_RNNLZD_STR-LNRLS sy-vline 
WA_RNNLZD_STR-ASHOSP sy-vline 
WA_RNNLZD_STR-GPART sy-vline 
WA_RNNLZD_STR-ROLTP sy-vline 
WA_RNNLZD_STR-ROLBZ sy-vline 
WA_RNNLZD_STR-PNAME sy-vline 
WA_RNNLZD_STR-EINRI sy-vline 
WA_RNNLZD_STR-FALNR sy-vline 
WA_RNNLZD_STR-BETRAG sy-vline 
WA_RNNLZD_STR-PROZENT sy-vline 
WA_RNNLZD_STR-AEQUI sy-vline 
WA_RNNLZD_STR-NNLZ sy-vline 
WA_RNNLZD_STR-MARK sy-vline 
WA_RNNLZD_STR-MODUS sy-vline      INTO ld_text SEPARATED BY SPACE.

*Add any further fields from structure WA_EKKO_STR you want to CONCATENATE...
ENDLOOP.
ENDFORM.