ABAP Select data from SAP table CLRS_FIELDS into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM CLRS_FIELDS
*  INTO TABLE @DATA(IT_CLRS_FIELDS2).
*--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_CLRS_FIELDS INDEX 1 INTO DATA(WA_CLRS_FIELDS2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<CLRS_FIELDS>-FIELDNAME = 1.
<CLRS_FIELDS>-GROUPKEY = 1.
<CLRS_FIELDS>-DATATYPE = 1.
<CLRS_FIELDS>-LENGTH = 1.
<CLRS_FIELDS>-DECIMALS = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_CLRS_FIELDS-WITHSIGN, sy-vline,
  WA_CLRS_FIELDS-PATTERN, sy-vline,
  WA_CLRS_FIELDS-CONV, sy-vline,
  WA_CLRS_FIELDS-UNIT, sy-vline,
  WA_CLRS_FIELDS-EXPONENT, sy-vline,
  WA_CLRS_FIELDS-WITHINTERVAL, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_CLRS_FIELDS 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_CLRS_FIELDS 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_CLRS_FIELDS INTO WA_CLRS_FIELDS.


*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 CUNIT, internal->external for field UNIT
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_CLRS_FIELDS-UNIT
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_CLRS_FIELDS-UNIT.
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_CLRS_FIELDS_STR, 
FIELDNAME TYPE STRING,
GROUPKEY TYPE STRING,
DATATYPE TYPE STRING,
LENGTH TYPE STRING,
DECIMALS TYPE STRING,
WITHSIGN TYPE STRING,
PATTERN TYPE STRING,
CONV TYPE STRING,
UNIT TYPE STRING,
EXPONENT TYPE STRING,
WITHINTERVAL TYPE STRING,END OF T_EKKO_STR.
DATA: WA_CLRS_FIELDS_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_CLRS_FIELDS_STR-FIELDNAME sy-vline 
WA_CLRS_FIELDS_STR-GROUPKEY sy-vline 
WA_CLRS_FIELDS_STR-DATATYPE sy-vline 
WA_CLRS_FIELDS_STR-LENGTH sy-vline 
WA_CLRS_FIELDS_STR-DECIMALS sy-vline 
WA_CLRS_FIELDS_STR-WITHSIGN sy-vline 
WA_CLRS_FIELDS_STR-PATTERN sy-vline 
WA_CLRS_FIELDS_STR-CONV sy-vline 
WA_CLRS_FIELDS_STR-UNIT sy-vline 
WA_CLRS_FIELDS_STR-EXPONENT sy-vline 
WA_CLRS_FIELDS_STR-WITHINTERVAL sy-vline      INTO ld_text SEPARATED BY SPACE.

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