ABAP Select data from SAP table DDFIELDVARS into internal table

Get Example source ABAP code based on a different SAP table
  Get ABAP code

Below is a number of ABAP code snippets to demonstrate how to select data from SAP DDFIELDVARS 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 DDFIELDVARS. 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 DDFIELDVARS 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_DDFIELDVARS TYPE STANDARD TABLE OF DDFIELDVARS,
      WA_DDFIELDVARS TYPE DDFIELDVARS,
      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: <DDFIELDVARS> TYPE DDFIELDVARS.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM DDFIELDVARS
*  INTO TABLE @DATA(IT_DDFIELDVARS2).
*--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_DDFIELDVARS INDEX 1 INTO DATA(WA_DDFIELDVARS2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<DDFIELDVARS>-FIELDNAME = 1.
<DDFIELDVARS>-POSITION = 1.
<DDFIELDVARS>-KEYFLAG = 1.
<DDFIELDVARS>-DATATYPE = 1.
<DDFIELDVARS>-LENG = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_DDFIELDVARS-DECIMALS, sy-vline,
  WA_DDFIELDVARS-NULLABLE, sy-vline,
  WA_DDFIELDVARS-SRS_ID, sy-vline,
  WA_DDFIELDVARS-DDDATATYPE, sy-vline,
  WA_DDFIELDVARS-INTTYPE, sy-vline,
  WA_DDFIELDVARS-INTLEN, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_DDFIELDVARS 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_DDFIELDVARS 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_DDFIELDVARS INTO WA_DDFIELDVARS.


*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 DTYPE, internal->external for field DATATYPE
CALL FUNCTION 'CONVERSION_EXIT_DTYPE_OUTPUT'
  EXPORTING
    input =                      WA_DDFIELDVARS-DATATYPE
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_DDFIELDVARS-DATATYPE.
WRITE:/ 'New Value:', ld_input.

*Conversion exit DTYPE, internal->external for field DDDATATYPE
CALL FUNCTION 'CONVERSION_EXIT_DTYPE_OUTPUT'
  EXPORTING
    input =                      WA_DDFIELDVARS-DDDATATYPE
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_DDFIELDVARS-DDDATATYPE.
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_DDFIELDVARS_STR, 
FIELDNAME TYPE STRING,
POSITION TYPE STRING,
KEYFLAG TYPE STRING,
DATATYPE TYPE STRING,
LENG TYPE STRING,
DECIMALS TYPE STRING,
NULLABLE TYPE STRING,
SRS_ID TYPE STRING,
DDDATATYPE TYPE STRING,
INTTYPE TYPE STRING,
INTLEN TYPE STRING,
ABDECIMALS TYPE STRING,
PROGTYPE TYPE STRING,
PROGLENG TYPE STRING,
PROGDECIMALS TYPE STRING,
TYPEVARIANTS TYPE STRING,
DECS_ARE_RELEVANT TYPE STRING,END OF T_EKKO_STR.
DATA: WA_DDFIELDVARS_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_DDFIELDVARS_STR-FIELDNAME sy-vline 
WA_DDFIELDVARS_STR-POSITION sy-vline 
WA_DDFIELDVARS_STR-KEYFLAG sy-vline 
WA_DDFIELDVARS_STR-DATATYPE sy-vline 
WA_DDFIELDVARS_STR-LENG sy-vline 
WA_DDFIELDVARS_STR-DECIMALS sy-vline 
WA_DDFIELDVARS_STR-NULLABLE sy-vline 
WA_DDFIELDVARS_STR-SRS_ID sy-vline 
WA_DDFIELDVARS_STR-DDDATATYPE sy-vline 
WA_DDFIELDVARS_STR-INTTYPE sy-vline 
WA_DDFIELDVARS_STR-INTLEN sy-vline 
WA_DDFIELDVARS_STR-ABDECIMALS sy-vline 
WA_DDFIELDVARS_STR-PROGTYPE sy-vline 
WA_DDFIELDVARS_STR-PROGLENG sy-vline 
WA_DDFIELDVARS_STR-PROGDECIMALS sy-vline 
WA_DDFIELDVARS_STR-TYPEVARIANTS sy-vline 
WA_DDFIELDVARS_STR-DECS_ARE_RELEVANT sy-vline      INTO ld_text SEPARATED BY SPACE.

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