ABAP Select data from SAP table REG30_ZW_A into internal table

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Below is a number of ABAP code snippets to demonstrate how to select data from SAP REG30_ZW_A 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 REG30_ZW_A. 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 REG30_ZW_A 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_REG30_ZW_A TYPE STANDARD TABLE OF REG30_ZW_A,
      WA_REG30_ZW_A TYPE REG30_ZW_A,
      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: <REG30_ZW_A> TYPE REG30_ZW_A.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_REG30_ZW_A.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM REG30_ZW_A
  INTO TABLE IT_REG30_ZW_A.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM REG30_ZW_A
*  INTO TABLE @DATA(IT_REG30_ZW_A2).
*--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_REG30_ZW_A INDEX 1 INTO DATA(WA_REG30_ZW_A2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_REG30_ZW_A ASSIGNING <REG30_ZW_A>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<REG30_ZW_A>-ZWNUMMERA = 1.
<REG30_ZW_A>-SPARTYPA = 1.
<REG30_ZW_A>-ZWTYPA = 1.
<REG30_ZW_A>-KENNZIFFA = 1.
<REG30_ZW_A>-BLIWIRKA = 1.

ENDLOOP.

LOOP AT IT_REG30_ZW_A INTO WA_REG30_ZW_A.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_REG30_ZW_A-ZWARTA, sy-vline,
  WA_REG30_ZW_A-ZWKENNA, sy-vline,
  WA_REG30_ZW_A-THGVERO, sy-vline,
  WA_REG30_ZW_A-ANZERGO, sy-vline,
  WA_REG30_ZW_A-ZWNABRO, sy-vline,
  WA_REG30_ZW_A-TARIFARTO, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_REG30_ZW_A 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_REG30_ZW_A 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_REG30_ZW_A INTO WA_REG30_ZW_A.


*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_REG30_ZW_A_STR, 
ZWNUMMERA TYPE STRING,
SPARTYPA TYPE STRING,
ZWTYPA TYPE STRING,
KENNZIFFA TYPE STRING,
BLIWIRKA TYPE STRING,
ZWARTA TYPE STRING,
ZWKENNA TYPE STRING,
THGVERO TYPE STRING,
ANZERGO TYPE STRING,
ZWNABRO TYPE STRING,
TARIFARTO TYPE STRING,
TEMP_AREAO TYPE STRING,
PR_AREA_AO TYPE STRING,
CALOR_AREO TYPE STRING,
HOEKORRO TYPE STRING,
PERVERBRO TYPE STRING,
GVERRECHO TYPE STRING,
KZAHLEA TYPE STRING,
KZAHLTA TYPE STRING,
GAS_PRS_ARA TYPE STRING,
CRGPRESSA TYPE STRING,
KONDIGRA TYPE STRING,
ABLSTATA TYPE STRING,
ZWNSETTLA TYPE STRING,END OF T_EKKO_STR.
DATA: WA_REG30_ZW_A_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_REG30_ZW_A_STR-ZWNUMMERA sy-vline 
WA_REG30_ZW_A_STR-SPARTYPA sy-vline 
WA_REG30_ZW_A_STR-ZWTYPA sy-vline 
WA_REG30_ZW_A_STR-KENNZIFFA sy-vline 
WA_REG30_ZW_A_STR-BLIWIRKA sy-vline 
WA_REG30_ZW_A_STR-ZWARTA sy-vline 
WA_REG30_ZW_A_STR-ZWKENNA sy-vline 
WA_REG30_ZW_A_STR-THGVERO sy-vline 
WA_REG30_ZW_A_STR-ANZERGO sy-vline 
WA_REG30_ZW_A_STR-ZWNABRO sy-vline 
WA_REG30_ZW_A_STR-TARIFARTO sy-vline 
WA_REG30_ZW_A_STR-TEMP_AREAO sy-vline 
WA_REG30_ZW_A_STR-PR_AREA_AO sy-vline 
WA_REG30_ZW_A_STR-CALOR_AREO sy-vline 
WA_REG30_ZW_A_STR-HOEKORRO sy-vline 
WA_REG30_ZW_A_STR-PERVERBRO sy-vline 
WA_REG30_ZW_A_STR-GVERRECHO sy-vline 
WA_REG30_ZW_A_STR-KZAHLEA sy-vline 
WA_REG30_ZW_A_STR-KZAHLTA sy-vline 
WA_REG30_ZW_A_STR-GAS_PRS_ARA sy-vline 
WA_REG30_ZW_A_STR-CRGPRESSA sy-vline 
WA_REG30_ZW_A_STR-KONDIGRA sy-vline 
WA_REG30_ZW_A_STR-ABLSTATA sy-vline 
WA_REG30_ZW_A_STR-ZWNSETTLA sy-vline      INTO ld_text SEPARATED BY SPACE.

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