ABAP Select data from SAP table WELP into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM WELP
*  INTO TABLE @DATA(IT_WELP2).
*--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_WELP INDEX 1 INTO DATA(WA_WELP2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<WELP>-MANDT = 1.
<WELP>-MBELN = 1.
<WELP>-MBELP = 1.
<WELP>-ERWRK = 1.
<WELP>-ERLNR = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_WELP-MBWNR, sy-vline,
  WA_WELP-VKORG, sy-vline,
  WA_WELP-VTWEG, sy-vline,
  WA_WELP-WERKS, sy-vline,
  WA_WELP-PLTYP, sy-vline,
  WA_WELP-KVEWE, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_WELP 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_WELP 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_WELP INTO WA_WELP.


*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 MBELN
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_WELP-MBELN
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_WELP-MBELN.
WRITE:/ 'New Value:', ld_input.

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

*Conversion exit KOTAB, internal->external for field KOTABNR
CALL FUNCTION 'CONVERSION_EXIT_KOTAB_OUTPUT'
  EXPORTING
    input =                      WA_WELP-KOTABNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_WELP-KOTABNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit MATN1, internal->external for field MATNR
CALL FUNCTION 'CONVERSION_EXIT_MATN1_OUTPUT'
  EXPORTING
    input =                      WA_WELP-MATNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_WELP-MATNR.
WRITE:/ 'New Value:', ld_input.

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

*Conversion exit CUNIT, internal->external for field MMEIN
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_WELP-MMEIN
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_WELP-MMEIN.
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_WELP_STR, 
MANDT TYPE STRING,
MBELN TYPE STRING,
MBELP TYPE STRING,
ERWRK TYPE STRING,
ERLNR TYPE STRING,
MBWNR TYPE STRING,
VKORG TYPE STRING,
VTWEG TYPE STRING,
WERKS TYPE STRING,
PLTYP TYPE STRING,
KVEWE TYPE STRING,
KAPPL TYPE STRING,
KSCHL TYPE STRING,
KOTABNR TYPE STRING,
KDUMMY TYPE STRING,
MATNR TYPE STRING,
VRKME TYPE STRING,
MBETR TYPE STRING,
MWAER TYPE STRING,
MPEIN TYPE STRING,
MMEIN TYPE STRING,
VKKAB TYPE STRING,
VKKBI TYPE STRING,
KNUMH TYPE STRING,
BPSTA TYPE STRING,
PDUMMY TYPE STRING,END OF T_EKKO_STR.
DATA: WA_WELP_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_WELP_STR-MANDT sy-vline 
WA_WELP_STR-MBELN sy-vline 
WA_WELP_STR-MBELP sy-vline 
WA_WELP_STR-ERWRK sy-vline 
WA_WELP_STR-ERLNR sy-vline 
WA_WELP_STR-MBWNR sy-vline 
WA_WELP_STR-VKORG sy-vline 
WA_WELP_STR-VTWEG sy-vline 
WA_WELP_STR-WERKS sy-vline 
WA_WELP_STR-PLTYP sy-vline 
WA_WELP_STR-KVEWE sy-vline 
WA_WELP_STR-KAPPL sy-vline 
WA_WELP_STR-KSCHL sy-vline 
WA_WELP_STR-KOTABNR sy-vline 
WA_WELP_STR-KDUMMY sy-vline 
WA_WELP_STR-MATNR sy-vline 
WA_WELP_STR-VRKME sy-vline 
WA_WELP_STR-MBETR sy-vline 
WA_WELP_STR-MWAER sy-vline 
WA_WELP_STR-MPEIN sy-vline 
WA_WELP_STR-MMEIN sy-vline 
WA_WELP_STR-VKKAB sy-vline 
WA_WELP_STR-VKKBI sy-vline 
WA_WELP_STR-KNUMH sy-vline 
WA_WELP_STR-BPSTA sy-vline 
WA_WELP_STR-PDUMMY sy-vline      INTO ld_text SEPARATED BY SPACE.

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