ABAP Select data from SAP table MCDDOWN into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM MCDDOWN
*  INTO TABLE @DATA(IT_MCDDOWN2).
*--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_MCDDOWN INDEX 1 INTO DATA(WA_MCDDOWN2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<MCDDOWN>-FCODE = 1.
<MCDDOWN>-DDICFELD = 1.
<MCDDOWN>-TABFELD = 1.
<MCDDOWN>-RANGES_SUF = 1.
<MCDDOWN>-DOMNAME = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_MCDDOWN-ROLLNAME, sy-vline,
  WA_MCDDOWN-OUTPUTLEN, sy-vline,
  WA_MCDDOWN-MEMORYID, sy-vline,
  WA_MCDDOWN-REPTEXT, sy-vline,
  WA_MCDDOWN-SCRTEXT_L, sy-vline,
  WA_MCDDOWN-SCRTEXT_M, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_MCDDOWN 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_MCDDOWN 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_MCDDOWN INTO WA_MCDDOWN.


*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_MCDDOWN_STR, 
FCODE TYPE STRING,
DDICFELD TYPE STRING,
TABFELD TYPE STRING,
RANGES_SUF TYPE STRING,
DOMNAME TYPE STRING,
ROLLNAME TYPE STRING,
OUTPUTLEN TYPE STRING,
MEMORYID TYPE STRING,
REPTEXT TYPE STRING,
SCRTEXT_L TYPE STRING,
SCRTEXT_M TYPE STRING,
SCRTEXT_S TYPE STRING,
CONVEXIT TYPE STRING,
KEYFLAG TYPE STRING,
ROLLNAME01 TYPE STRING,
LISTE_NEU_AUFBAUEN TYPE STRING,
KETT_AKT TYPE STRING,
OBJECT TYPE STRING,
DUMMY00 TYPE STRING,
DUMMY01 TYPE STRING,
DUMMY02 TYPE STRING,
DUMMY03 TYPE STRING,
DUMMY04 TYPE STRING,
DUMMY05 TYPE STRING,
DUMMY06 TYPE STRING,
DUMMY07 TYPE STRING,
DUMMY08 TYPE STRING,
DUMMY09 TYPE STRING,
DUMMY10 TYPE STRING,
DUMMY11 TYPE STRING,END OF T_EKKO_STR.
DATA: WA_MCDDOWN_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_MCDDOWN_STR-FCODE sy-vline 
WA_MCDDOWN_STR-DDICFELD sy-vline 
WA_MCDDOWN_STR-TABFELD sy-vline 
WA_MCDDOWN_STR-RANGES_SUF sy-vline 
WA_MCDDOWN_STR-DOMNAME sy-vline 
WA_MCDDOWN_STR-ROLLNAME sy-vline 
WA_MCDDOWN_STR-OUTPUTLEN sy-vline 
WA_MCDDOWN_STR-MEMORYID sy-vline 
WA_MCDDOWN_STR-REPTEXT sy-vline 
WA_MCDDOWN_STR-SCRTEXT_L sy-vline 
WA_MCDDOWN_STR-SCRTEXT_M sy-vline 
WA_MCDDOWN_STR-SCRTEXT_S sy-vline 
WA_MCDDOWN_STR-CONVEXIT sy-vline 
WA_MCDDOWN_STR-KEYFLAG sy-vline 
WA_MCDDOWN_STR-ROLLNAME01 sy-vline 
WA_MCDDOWN_STR-LISTE_NEU_AUFBAUEN sy-vline 
WA_MCDDOWN_STR-KETT_AKT sy-vline 
WA_MCDDOWN_STR-OBJECT sy-vline 
WA_MCDDOWN_STR-DUMMY00 sy-vline 
WA_MCDDOWN_STR-DUMMY01 sy-vline 
WA_MCDDOWN_STR-DUMMY02 sy-vline 
WA_MCDDOWN_STR-DUMMY03 sy-vline 
WA_MCDDOWN_STR-DUMMY04 sy-vline 
WA_MCDDOWN_STR-DUMMY05 sy-vline 
WA_MCDDOWN_STR-DUMMY06 sy-vline 
WA_MCDDOWN_STR-DUMMY07 sy-vline 
WA_MCDDOWN_STR-DUMMY08 sy-vline 
WA_MCDDOWN_STR-DUMMY09 sy-vline 
WA_MCDDOWN_STR-DUMMY10 sy-vline 
WA_MCDDOWN_STR-DUMMY11 sy-vline      INTO ld_text SEPARATED BY SPACE.

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