ABAP Select data from SAP table MWWS1 into internal table

Get Example source ABAP code based on a different SAP table
  Get ABAP code

Below is a number of ABAP code snippets to demonstrate how to select data from SAP MWWS1 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 MWWS1. 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 MWWS1 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_MWWS1 TYPE STANDARD TABLE OF MWWS1,
      WA_MWWS1 TYPE MWWS1,
      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: <MWWS1> TYPE MWWS1.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_MWWS1.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM MWWS1
  INTO TABLE IT_MWWS1.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM MWWS1
*  INTO TABLE @DATA(IT_MWWS12).
*--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_MWWS1 INDEX 1 INTO DATA(WA_MWWS12).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_MWWS1 ASSIGNING <MWWS1>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<MWWS1>-ERSDA = 1.
<MWWS1>-ERNAM = 1.
<MWWS1>-LAEDA = 1.
<MWWS1>-AENAM = 1.
<MWWS1>-VPSTA = 1.

ENDLOOP.

LOOP AT IT_MWWS1 INTO WA_MWWS1.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_MWWS1-PSTAT, sy-vline,
  WA_MWWS1-LVORM, sy-vline,
  WA_MWWS1-MTART, sy-vline,
  WA_MWWS1-MBRSH, sy-vline,
  WA_MWWS1-MATKL, sy-vline,
  WA_MWWS1-BISMT, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_MWWS1 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_MWWS1 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_MWWS1 INTO WA_MWWS1.


*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 MEINS
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_MWWS1-MEINS
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_MWWS1-MEINS.
WRITE:/ 'New Value:', ld_input.

*Conversion exit CUNIT, internal->external for field BSTME
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_MWWS1-BSTME
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_MWWS1-BSTME.
WRITE:/ 'New Value:', ld_input.

*Conversion exit ALPHA, internal->external for field KUNNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_MWWS1-KUNNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_MWWS1-KUNNR.
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_MWWS1_STR, 
ERSDA TYPE STRING,
ERNAM TYPE STRING,
LAEDA TYPE STRING,
AENAM TYPE STRING,
VPSTA TYPE STRING,
PSTAT TYPE STRING,
LVORM TYPE STRING,
MTART TYPE STRING,
MBRSH TYPE STRING,
MATKL TYPE STRING,
BISMT TYPE STRING,
MEINS TYPE STRING,
BSTME TYPE STRING,
DISST TYPE STRING,
SPART TYPE STRING,
KUNNR TYPE STRING,
EANNR TYPE STRING,
WESCH TYPE STRING,
BWVOR TYPE STRING,
BWSCL TYPE STRING,
SAISO TYPE STRING,
ETIAR TYPE STRING,
ETIFO TYPE STRING,
ENTAR TYPE STRING,
MAKTX TYPE STRING,
ATTYP TYPE STRING,END OF T_EKKO_STR.
DATA: WA_MWWS1_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_MWWS1_STR-ERSDA sy-vline 
WA_MWWS1_STR-ERNAM sy-vline 
WA_MWWS1_STR-LAEDA sy-vline 
WA_MWWS1_STR-AENAM sy-vline 
WA_MWWS1_STR-VPSTA sy-vline 
WA_MWWS1_STR-PSTAT sy-vline 
WA_MWWS1_STR-LVORM sy-vline 
WA_MWWS1_STR-MTART sy-vline 
WA_MWWS1_STR-MBRSH sy-vline 
WA_MWWS1_STR-MATKL sy-vline 
WA_MWWS1_STR-BISMT sy-vline 
WA_MWWS1_STR-MEINS sy-vline 
WA_MWWS1_STR-BSTME sy-vline 
WA_MWWS1_STR-DISST sy-vline 
WA_MWWS1_STR-SPART sy-vline 
WA_MWWS1_STR-KUNNR sy-vline 
WA_MWWS1_STR-EANNR sy-vline 
WA_MWWS1_STR-WESCH sy-vline 
WA_MWWS1_STR-BWVOR sy-vline 
WA_MWWS1_STR-BWSCL sy-vline 
WA_MWWS1_STR-SAISO sy-vline 
WA_MWWS1_STR-ETIAR sy-vline 
WA_MWWS1_STR-ETIFO sy-vline 
WA_MWWS1_STR-ENTAR sy-vline 
WA_MWWS1_STR-MAKTX sy-vline 
WA_MWWS1_STR-ATTYP sy-vline      INTO ld_text SEPARATED BY SPACE.

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