ABAP Select data from SAP table SNIWELS into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM SNIWELS
*  INTO TABLE @DATA(IT_SNIWELS2).
*--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_SNIWELS INDEX 1 INTO DATA(WA_SNIWELS2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<SNIWELS>-BROAD = 1.
<SNIWELS>-NARRW = 1.
<SNIWELS>-MYALV = 1.
<SNIWELS>-PRNTL = 1.
<SNIWELS>-CONTO = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_SNIWELS-ARCHV, sy-vline,
  WA_SNIWELS-PARLS, sy-vline,
  WA_SNIWELS-ERRLS, sy-vline,
  WA_SNIWELS-STATL, sy-vline,
  WA_SNIWELS-COMLS, sy-vline,
  WA_SNIWELS-SINLN, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_SNIWELS 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_SNIWELS 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_SNIWELS INTO WA_SNIWELS.


*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_SNIWELS_STR, 
BROAD TYPE STRING,
NARRW TYPE STRING,
MYALV TYPE STRING,
PRNTL TYPE STRING,
CONTO TYPE STRING,
ARCHV TYPE STRING,
PARLS TYPE STRING,
ERRLS TYPE STRING,
STATL TYPE STRING,
COMLS TYPE STRING,
SINLN TYPE STRING,
NOSTK TYPE STRING,
LIGHT TYPE STRING,
DEVAL TYPE STRING,
SUMLN TYPE STRING,
LSDOC TYPE STRING,
XOLD TYPE STRING,END OF T_EKKO_STR.
DATA: WA_SNIWELS_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_SNIWELS_STR-BROAD sy-vline 
WA_SNIWELS_STR-NARRW sy-vline 
WA_SNIWELS_STR-MYALV sy-vline 
WA_SNIWELS_STR-PRNTL sy-vline 
WA_SNIWELS_STR-CONTO sy-vline 
WA_SNIWELS_STR-ARCHV sy-vline 
WA_SNIWELS_STR-PARLS sy-vline 
WA_SNIWELS_STR-ERRLS sy-vline 
WA_SNIWELS_STR-STATL sy-vline 
WA_SNIWELS_STR-COMLS sy-vline 
WA_SNIWELS_STR-SINLN sy-vline 
WA_SNIWELS_STR-NOSTK sy-vline 
WA_SNIWELS_STR-LIGHT sy-vline 
WA_SNIWELS_STR-DEVAL sy-vline 
WA_SNIWELS_STR-SUMLN sy-vline 
WA_SNIWELS_STR-LSDOC sy-vline 
WA_SNIWELS_STR-XOLD sy-vline      INTO ld_text SEPARATED BY SPACE.

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