ABAP Select data from SAP table M_MWAKD into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM M_MWAKD
*  INTO TABLE @DATA(IT_M_MWAKD2).
*--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_M_MWAKD INDEX 1 INTO DATA(WA_M_MWAKD2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<M_MWAKD>-MANDT = 1.
<M_MWAKD>-FIGRP = 1.
<M_MWAKD>-FILNR = 1.
<M_MWAKD>-EKORB = 1.
<M_MWAKD>-EKGRB = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_M_MWAKD-LFNRU, sy-vline,
  WA_M_MWAKD-VZENT, sy-vline,
  WA_M_MWAKD-ABELN, sy-vline,
  WA_M_MWAKD-ABELP, sy-vline,
  WA_M_MWAKD-ABELG, sy-vline,
  WA_M_MWAKD-ABELF, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_M_MWAKD 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_M_MWAKD 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_M_MWAKD INTO WA_M_MWAKD.


*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 ALPHA, internal->external for field FILNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_M_MWAKD-FILNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_M_MWAKD-FILNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field LFNRU
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_M_MWAKD-LFNRU
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_M_MWAKD-LFNRU.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field VZENT
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_M_MWAKD-VZENT
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_M_MWAKD-VZENT.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field ABELN
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_M_MWAKD-ABELN
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_M_MWAKD-ABELN.
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_M_MWAKD_STR, 
MANDT TYPE STRING,
FIGRP TYPE STRING,
FILNR TYPE STRING,
EKORB TYPE STRING,
EKGRB TYPE STRING,
LFNRU TYPE STRING,
VZENT TYPE STRING,
ABELN TYPE STRING,
ABELP TYPE STRING,
ABELG TYPE STRING,
ABELF TYPE STRING,
AUFAR TYPE STRING,END OF T_EKKO_STR.
DATA: WA_M_MWAKD_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_M_MWAKD_STR-MANDT sy-vline 
WA_M_MWAKD_STR-FIGRP sy-vline 
WA_M_MWAKD_STR-FILNR sy-vline 
WA_M_MWAKD_STR-EKORB sy-vline 
WA_M_MWAKD_STR-EKGRB sy-vline 
WA_M_MWAKD_STR-LFNRU sy-vline 
WA_M_MWAKD_STR-VZENT sy-vline 
WA_M_MWAKD_STR-ABELN sy-vline 
WA_M_MWAKD_STR-ABELP sy-vline 
WA_M_MWAKD_STR-ABELG sy-vline 
WA_M_MWAKD_STR-ABELF sy-vline 
WA_M_MWAKD_STR-AUFAR sy-vline      INTO ld_text SEPARATED BY SPACE.

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