ABAP Select data from SAP table GNSVB into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM GNSVB
*  INTO TABLE @DATA(IT_GNSVB2).
*--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_GNSVB INDEX 1 INTO DATA(WA_GNSVB2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<GNSVB>-MANDT = 1.
<GNSVB>-OBJNR = 1.
<GNSVB>-COUNTER = 1.
<GNSVB>-COUNTERS = 1.
<GNSVB>-GENPAUS = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_GNSVB-GENNAME, sy-vline,
  WA_GNSVB-GENDATUM, sy-vline,
  WA_GNSVB-GENTIME, sy-vline,
  WA_GNSVB-GENVDATE, sy-vline,
  WA_GNSVB-GENBDATE, sy-vline,
  WA_GNSVB-GENVTIME, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_GNSVB 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_GNSVB 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_GNSVB INTO WA_GNSVB.


*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_GNSVB_STR, 
MANDT TYPE STRING,
OBJNR TYPE STRING,
COUNTER TYPE STRING,
COUNTERS TYPE STRING,
GENPAUS TYPE STRING,
GENNAME TYPE STRING,
GENDATUM TYPE STRING,
GENTIME TYPE STRING,
GENVDATE TYPE STRING,
GENBDATE TYPE STRING,
GENVTIME TYPE STRING,
GENBTIME TYPE STRING,
GENINAME TYPE STRING,
GENIDATE TYPE STRING,
GENITIME TYPE STRING,
GENIAKT TYPE STRING,
K_GENEHM TYPE STRING,
GENVNAME TYPE STRING,
AKTIV TYPE STRING,
LVORM TYPE STRING,
INSERT TYPE STRING,
UPDATE TYPE STRING,
DELETE TYPE STRING,END OF T_EKKO_STR.
DATA: WA_GNSVB_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_GNSVB_STR-MANDT sy-vline 
WA_GNSVB_STR-OBJNR sy-vline 
WA_GNSVB_STR-COUNTER sy-vline 
WA_GNSVB_STR-COUNTERS sy-vline 
WA_GNSVB_STR-GENPAUS sy-vline 
WA_GNSVB_STR-GENNAME sy-vline 
WA_GNSVB_STR-GENDATUM sy-vline 
WA_GNSVB_STR-GENTIME sy-vline 
WA_GNSVB_STR-GENVDATE sy-vline 
WA_GNSVB_STR-GENBDATE sy-vline 
WA_GNSVB_STR-GENVTIME sy-vline 
WA_GNSVB_STR-GENBTIME sy-vline 
WA_GNSVB_STR-GENINAME sy-vline 
WA_GNSVB_STR-GENIDATE sy-vline 
WA_GNSVB_STR-GENITIME sy-vline 
WA_GNSVB_STR-GENIAKT sy-vline 
WA_GNSVB_STR-K_GENEHM sy-vline 
WA_GNSVB_STR-GENVNAME sy-vline 
WA_GNSVB_STR-AKTIV sy-vline 
WA_GNSVB_STR-LVORM sy-vline 
WA_GNSVB_STR-INSERT sy-vline 
WA_GNSVB_STR-UPDATE sy-vline 
WA_GNSVB_STR-DELETE sy-vline      INTO ld_text SEPARATED BY SPACE.

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