ABAP Select data from SAP table TCNV 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 TCNV 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 TCNV. 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 TCNV 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_TCNV TYPE STANDARD TABLE OF TCNV,
      WA_TCNV TYPE TCNV,
      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: <TCNV> TYPE TCNV.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM TCNV
*  INTO TABLE @DATA(IT_TCNV2).
*--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_TCNV INDEX 1 INTO DATA(WA_TCNV2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<TCNV>-TABNAME = 1.
<TCNV>-FUNC = 1.
<TCNV>-SRCTAB = 1.
<TCNV>-DESTTAB = 1.
<TCNV>-ACTMODE = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_TCNV-TEMPNAME, sy-vline,
  WA_TCNV-STEP1, sy-vline,
  WA_TCNV-STEP2, sy-vline,
  WA_TCNV-STEP3, sy-vline,
  WA_TCNV-STEP4, sy-vline,
  WA_TCNV-STEP5, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_TCNV 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_TCNV 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_TCNV INTO WA_TCNV.


*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_TCNV_STR, 
TABNAME TYPE STRING,
FUNC TYPE STRING,
SRCTAB TYPE STRING,
DESTTAB TYPE STRING,
ACTMODE TYPE STRING,
TEMPNAME TYPE STRING,
STEP1 TYPE STRING,
STEP2 TYPE STRING,
STEP3 TYPE STRING,
STEP4 TYPE STRING,
STEP5 TYPE STRING,
STEP6 TYPE STRING,
CDATE TYPE STRING,
CTIME TYPE STRING,
CUSER TYPE STRING,
BUFSTATE TYPE STRING,
MCODE TYPE STRING,
TABLOG TYPE STRING,
NTMOD TYPE STRING,
CLIENT_ADD TYPE STRING,END OF T_EKKO_STR.
DATA: WA_TCNV_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_TCNV_STR-TABNAME sy-vline 
WA_TCNV_STR-FUNC sy-vline 
WA_TCNV_STR-SRCTAB sy-vline 
WA_TCNV_STR-DESTTAB sy-vline 
WA_TCNV_STR-ACTMODE sy-vline 
WA_TCNV_STR-TEMPNAME sy-vline 
WA_TCNV_STR-STEP1 sy-vline 
WA_TCNV_STR-STEP2 sy-vline 
WA_TCNV_STR-STEP3 sy-vline 
WA_TCNV_STR-STEP4 sy-vline 
WA_TCNV_STR-STEP5 sy-vline 
WA_TCNV_STR-STEP6 sy-vline 
WA_TCNV_STR-CDATE sy-vline 
WA_TCNV_STR-CTIME sy-vline 
WA_TCNV_STR-CUSER sy-vline 
WA_TCNV_STR-BUFSTATE sy-vline 
WA_TCNV_STR-MCODE sy-vline 
WA_TCNV_STR-TABLOG sy-vline 
WA_TCNV_STR-NTMOD sy-vline 
WA_TCNV_STR-CLIENT_ADD sy-vline      INTO ld_text SEPARATED BY SPACE.

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