ABAP Select data from SAP table CAT_DP_FOR into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM CAT_DP_FOR
*  INTO TABLE @DATA(IT_CAT_DP_FOR2).
*--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_CAT_DP_FOR INDEX 1 INTO DATA(WA_CAT_DP_FOR2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<CAT_DP_FOR>-ABLNR = 1.
<CAT_DP_FOR>-COMMID = 1.
<CAT_DP_FOR>-SUBID = 1.
<CAT_DP_FOR>-CALLNO = 1.
<CAT_DP_FOR>-LINNO = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_CAT_DP_FOR-TABNAME, sy-vline,
  WA_CAT_DP_FOR-FIELDNAME, sy-vline,
  WA_CAT_DP_FOR-IPOSITION, sy-vline,
  WA_CAT_DP_FOR-IOFFSET, sy-vline,
  WA_CAT_DP_FOR-INTLENGTH, sy-vline,
  WA_CAT_DP_FOR-DECIMALS, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_CAT_DP_FOR 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_CAT_DP_FOR 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_CAT_DP_FOR INTO WA_CAT_DP_FOR.


*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.
ENDFORM. 

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

TYPES: BEGIN OF T_CAT_DP_FOR_STR, 
ABLNR TYPE STRING,
COMMID TYPE STRING,
SUBID TYPE STRING,
CALLNO TYPE STRING,
LINNO TYPE STRING,
TABNAME TYPE STRING,
FIELDNAME TYPE STRING,
IPOSITION TYPE STRING,
IOFFSET TYPE STRING,
INTLENGTH TYPE STRING,
DECIMALS TYPE STRING,
EXID TYPE STRING,END OF T_EKKO_STR.
DATA: WA_CAT_DP_FOR_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_CAT_DP_FOR_STR-ABLNR sy-vline 
WA_CAT_DP_FOR_STR-COMMID sy-vline 
WA_CAT_DP_FOR_STR-SUBID sy-vline 
WA_CAT_DP_FOR_STR-CALLNO sy-vline 
WA_CAT_DP_FOR_STR-LINNO sy-vline 
WA_CAT_DP_FOR_STR-TABNAME sy-vline 
WA_CAT_DP_FOR_STR-FIELDNAME sy-vline 
WA_CAT_DP_FOR_STR-IPOSITION sy-vline 
WA_CAT_DP_FOR_STR-IOFFSET sy-vline 
WA_CAT_DP_FOR_STR-INTLENGTH sy-vline 
WA_CAT_DP_FOR_STR-DECIMALS sy-vline 
WA_CAT_DP_FOR_STR-EXID sy-vline      INTO ld_text SEPARATED BY SPACE.

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