ABAP Select data from SAP table DNTAB into internal table

Get Example source ABAP code based on a different SAP table
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Below is a number of ABAP code snippets to demonstrate how to select data from SAP DNTAB 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 DNTAB. 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 DNTAB 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_DNTAB TYPE STANDARD TABLE OF DNTAB,
      WA_DNTAB TYPE DNTAB,
      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: <DNTAB> TYPE DNTAB.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM DNTAB
*  INTO TABLE @DATA(IT_DNTAB2).
*--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_DNTAB INDEX 1 INTO DATA(WA_DNTAB2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<DNTAB>-TABNAME = 1.
<DNTAB>-FIELDNAME = 1.
<DNTAB>-LANGU = 1.
<DNTAB>-POSITION = 1.
<DNTAB>-OFFSET = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_DNTAB-KEYFLAG, sy-vline,
  WA_DNTAB-FIELDTEXT, sy-vline,
  WA_DNTAB-DATATYPE, sy-vline,
  WA_DNTAB-INTTYPE, sy-vline,
  WA_DNTAB-DDLEN, sy-vline,
  WA_DNTAB-INTLEN, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_DNTAB 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_DNTAB 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_DNTAB INTO WA_DNTAB.


*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 ISOLA, internal->external for field LANGU
CALL FUNCTION 'CONVERSION_EXIT_ISOLA_OUTPUT'
  EXPORTING
    input =                      WA_DNTAB-LANGU
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_DNTAB-LANGU.
WRITE:/ 'New Value:', ld_input.

*Conversion exit DTYPE, internal->external for field DATATYPE
CALL FUNCTION 'CONVERSION_EXIT_DTYPE_OUTPUT'
  EXPORTING
    input =                      WA_DNTAB-DATATYPE
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_DNTAB-DATATYPE.
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_DNTAB_STR, 
TABNAME TYPE STRING,
FIELDNAME TYPE STRING,
LANGU TYPE STRING,
POSITION TYPE STRING,
OFFSET TYPE STRING,
KEYFLAG TYPE STRING,
FIELDTEXT TYPE STRING,
DATATYPE TYPE STRING,
INTTYPE TYPE STRING,
DDLEN TYPE STRING,
INTLEN TYPE STRING,
DECIMALS TYPE STRING,
CHECKTABLE TYPE STRING,
REFTABLE TYPE STRING,
REFFIELD TYPE STRING,
PRECFIELD TYPE STRING,
LOGFLAG TYPE STRING,
MEMORYID TYPE STRING,
LOWERCASE TYPE STRING,
SIGN TYPE STRING,
VALEXI TYPE STRING,
NOFORKEY TYPE STRING,
CONVEXIT TYPE STRING,END OF T_EKKO_STR.
DATA: WA_DNTAB_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_DNTAB_STR-TABNAME sy-vline 
WA_DNTAB_STR-FIELDNAME sy-vline 
WA_DNTAB_STR-LANGU sy-vline 
WA_DNTAB_STR-POSITION sy-vline 
WA_DNTAB_STR-OFFSET sy-vline 
WA_DNTAB_STR-KEYFLAG sy-vline 
WA_DNTAB_STR-FIELDTEXT sy-vline 
WA_DNTAB_STR-DATATYPE sy-vline 
WA_DNTAB_STR-INTTYPE sy-vline 
WA_DNTAB_STR-DDLEN sy-vline 
WA_DNTAB_STR-INTLEN sy-vline 
WA_DNTAB_STR-DECIMALS sy-vline 
WA_DNTAB_STR-CHECKTABLE sy-vline 
WA_DNTAB_STR-REFTABLE sy-vline 
WA_DNTAB_STR-REFFIELD sy-vline 
WA_DNTAB_STR-PRECFIELD sy-vline 
WA_DNTAB_STR-LOGFLAG sy-vline 
WA_DNTAB_STR-MEMORYID sy-vline 
WA_DNTAB_STR-LOWERCASE sy-vline 
WA_DNTAB_STR-SIGN sy-vline 
WA_DNTAB_STR-VALEXI sy-vline 
WA_DNTAB_STR-NOFORKEY sy-vline 
WA_DNTAB_STR-CONVEXIT sy-vline      INTO ld_text SEPARATED BY SPACE.

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