ABAP Select data from SAP table DDCNVEXIT 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 DDCNVEXIT 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 DDCNVEXIT. 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 DDCNVEXIT 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_DDCNVEXIT TYPE STANDARD TABLE OF DDCNVEXIT,
      WA_DDCNVEXIT TYPE DDCNVEXIT,
      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: <DDCNVEXIT> TYPE DDCNVEXIT.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM DDCNVEXIT
*  INTO TABLE @DATA(IT_DDCNVEXIT2).
*--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_DDCNVEXIT INDEX 1 INTO DATA(WA_DDCNVEXIT2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<DDCNVEXIT>-CNVCONTEXT = 1.
<DDCNVEXIT>-TABNAME = 1.
<DDCNVEXIT>-C_INIT = 1.
<DDCNVEXIT>-C_INIT_R = 1.
<DDCNVEXIT>-C_AHEAD = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_DDCNVEXIT-C_AHEAD_R, sy-vline,
  WA_DDCNVEXIT-C_LOCK, sy-vline,
  WA_DDCNVEXIT-C_LOCK_R, sy-vline,
  WA_DDCNVEXIT-C_FETCH, sy-vline,
  WA_DDCNVEXIT-C_FETCH_R, sy-vline,
  WA_DDCNVEXIT-C_MAP, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_DDCNVEXIT 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_DDCNVEXIT 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_DDCNVEXIT INTO WA_DDCNVEXIT.


*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_DDCNVEXIT_STR, 
CNVCONTEXT TYPE STRING,
TABNAME TYPE STRING,
C_INIT TYPE STRING,
C_INIT_R TYPE STRING,
C_AHEAD TYPE STRING,
C_AHEAD_R TYPE STRING,
C_LOCK TYPE STRING,
C_LOCK_R TYPE STRING,
C_FETCH TYPE STRING,
C_FETCH_R TYPE STRING,
C_MAP TYPE STRING,
C_MAP_R TYPE STRING,
C_MAP_METHOD TYPE STRING,
C_MAP_CLASS TYPE STRING,
C_INSERT TYPE STRING,
C_INSERT_R TYPE STRING,
C_UPDATE TYPE STRING,
C_UPDATE_R TYPE STRING,
C_UNLOCK TYPE STRING,
C_UNLOCK_R TYPE STRING,
C_FINISH TYPE STRING,
C_FINISH_R TYPE STRING,
C_AHEADD TYPE STRING,
C_AHEADD_R TYPE STRING,
C_DELETE TYPE STRING,
C_DELETE_R TYPE STRING,
LOGNAME TYPE STRING,
SQL_ENABLED TYPE STRING,END OF T_EKKO_STR.
DATA: WA_DDCNVEXIT_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_DDCNVEXIT_STR-CNVCONTEXT sy-vline 
WA_DDCNVEXIT_STR-TABNAME sy-vline 
WA_DDCNVEXIT_STR-C_INIT sy-vline 
WA_DDCNVEXIT_STR-C_INIT_R sy-vline 
WA_DDCNVEXIT_STR-C_AHEAD sy-vline 
WA_DDCNVEXIT_STR-C_AHEAD_R sy-vline 
WA_DDCNVEXIT_STR-C_LOCK sy-vline 
WA_DDCNVEXIT_STR-C_LOCK_R sy-vline 
WA_DDCNVEXIT_STR-C_FETCH sy-vline 
WA_DDCNVEXIT_STR-C_FETCH_R sy-vline 
WA_DDCNVEXIT_STR-C_MAP sy-vline 
WA_DDCNVEXIT_STR-C_MAP_R sy-vline 
WA_DDCNVEXIT_STR-C_MAP_METHOD sy-vline 
WA_DDCNVEXIT_STR-C_MAP_CLASS sy-vline 
WA_DDCNVEXIT_STR-C_INSERT sy-vline 
WA_DDCNVEXIT_STR-C_INSERT_R sy-vline 
WA_DDCNVEXIT_STR-C_UPDATE sy-vline 
WA_DDCNVEXIT_STR-C_UPDATE_R sy-vline 
WA_DDCNVEXIT_STR-C_UNLOCK sy-vline 
WA_DDCNVEXIT_STR-C_UNLOCK_R sy-vline 
WA_DDCNVEXIT_STR-C_FINISH sy-vline 
WA_DDCNVEXIT_STR-C_FINISH_R sy-vline 
WA_DDCNVEXIT_STR-C_AHEADD sy-vline 
WA_DDCNVEXIT_STR-C_AHEADD_R sy-vline 
WA_DDCNVEXIT_STR-C_DELETE sy-vline 
WA_DDCNVEXIT_STR-C_DELETE_R sy-vline 
WA_DDCNVEXIT_STR-LOGNAME sy-vline 
WA_DDCNVEXIT_STR-SQL_ENABLED sy-vline      INTO ld_text SEPARATED BY SPACE.

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