ABAP Select data from SAP table RFC_METADATA_DDIC into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM RFC_METADATA_DDIC
*  INTO TABLE @DATA(IT_RFC_METADATA_DDIC2).
*--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_RFC_METADATA_DDIC INDEX 1 INTO DATA(WA_RFC_METADATA_DDIC2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<RFC_METADATA_DDIC>-TYPENAME = 1.
<RFC_METADATA_DDIC>-FIELDNAME = 1.
<RFC_METADATA_DDIC>-COMPTYPE = 1.
<RFC_METADATA_DDIC>-FIELDTYPE = 1.
<RFC_METADATA_DDIC>-DATATYPE = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_RFC_METADATA_DDIC-TABLENGTH, sy-vline,
  WA_RFC_METADATA_DDIC-TABLENGTH_UC, sy-vline,
  WA_RFC_METADATA_DDIC-DESCRIPTION, sy-vline,
  WA_RFC_METADATA_DDIC-DECIMALS, sy-vline,
  WA_RFC_METADATA_DDIC-INTTYPE, sy-vline,
  WA_RFC_METADATA_DDIC-OFFSET, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_RFC_METADATA_DDIC 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_RFC_METADATA_DDIC 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_RFC_METADATA_DDIC INTO WA_RFC_METADATA_DDIC.


*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_RFC_METADATA_DDIC-DATATYPE
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_RFC_METADATA_DDIC-DATATYPE.
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_RFC_METADATA_DDIC_STR, 
TYPENAME TYPE STRING,
FIELDNAME TYPE STRING,
COMPTYPE TYPE STRING,
FIELDTYPE TYPE STRING,
DATATYPE TYPE STRING,
TABLENGTH TYPE STRING,
TABLENGTH_UC TYPE STRING,
DESCRIPTION TYPE STRING,
DECIMALS TYPE STRING,
INTTYPE TYPE STRING,
OFFSET TYPE STRING,
OFFSET_UC TYPE STRING,
INTLEN TYPE STRING,
INTLEN_UC TYPE STRING,
TIMESTAMP TYPE STRING,END OF T_EKKO_STR.
DATA: WA_RFC_METADATA_DDIC_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_RFC_METADATA_DDIC_STR-TYPENAME sy-vline 
WA_RFC_METADATA_DDIC_STR-FIELDNAME sy-vline 
WA_RFC_METADATA_DDIC_STR-COMPTYPE sy-vline 
WA_RFC_METADATA_DDIC_STR-FIELDTYPE sy-vline 
WA_RFC_METADATA_DDIC_STR-DATATYPE sy-vline 
WA_RFC_METADATA_DDIC_STR-TABLENGTH sy-vline 
WA_RFC_METADATA_DDIC_STR-TABLENGTH_UC sy-vline 
WA_RFC_METADATA_DDIC_STR-DESCRIPTION sy-vline 
WA_RFC_METADATA_DDIC_STR-DECIMALS sy-vline 
WA_RFC_METADATA_DDIC_STR-INTTYPE sy-vline 
WA_RFC_METADATA_DDIC_STR-OFFSET sy-vline 
WA_RFC_METADATA_DDIC_STR-OFFSET_UC sy-vline 
WA_RFC_METADATA_DDIC_STR-INTLEN sy-vline 
WA_RFC_METADATA_DDIC_STR-INTLEN_UC sy-vline 
WA_RFC_METADATA_DDIC_STR-TIMESTAMP sy-vline      INTO ld_text SEPARATED BY SPACE.

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