ABAP Select data from SAP table TWZLA 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 TWZLA 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 TWZLA. 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 TWZLA 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_TWZLA TYPE STANDARD TABLE OF TWZLA,
      WA_TWZLA TYPE TWZLA,
      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: <TWZLA> TYPE TWZLA.

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM TWZLA
*  INTO TABLE @DATA(IT_TWZLA2).
*--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_TWZLA INDEX 1 INTO DATA(WA_TWZLA2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<TWZLA>-MANDT = 1.
<TWZLA>-LFDNR = 1.
<TWZLA>-ATTYP = 1.
<TWZLA>-KEYTR = 1.
<TWZLA>-VLFKZ = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_TWZLA-VKORG, sy-vline,
  WA_TWZLA-VTWEG, sy-vline,
  WA_TWZLA-WERKS, sy-vline,
  WA_TWZLA-KUNNR, sy-vline,
  WA_TWZLA-STRNR, sy-vline,
  WA_TWZLA-KZKSN, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_TWZLA 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_TWZLA 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_TWZLA INTO WA_TWZLA.


*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 ALPHA, internal->external for field KUNNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_TWZLA-KUNNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_TWZLA-KUNNR.
WRITE:/ 'New Value:', ld_input.

*Conversion exit MATN1, internal->external for field STRNR
CALL FUNCTION 'CONVERSION_EXIT_MATN1_OUTPUT'
  EXPORTING
    input =                      WA_TWZLA-STRNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_TWZLA-STRNR.
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_TWZLA_STR, 
MANDT TYPE STRING,
LFDNR TYPE STRING,
ATTYP TYPE STRING,
KEYTR TYPE STRING,
VLFKZ TYPE STRING,
VKORG TYPE STRING,
VTWEG TYPE STRING,
WERKS TYPE STRING,
KUNNR TYPE STRING,
STRNR TYPE STRING,
KZKSN TYPE STRING,
KZPCN TYPE STRING,
RPLFL TYPE STRING,END OF T_EKKO_STR.
DATA: WA_TWZLA_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_TWZLA_STR-MANDT sy-vline 
WA_TWZLA_STR-LFDNR sy-vline 
WA_TWZLA_STR-ATTYP sy-vline 
WA_TWZLA_STR-KEYTR sy-vline 
WA_TWZLA_STR-VLFKZ sy-vline 
WA_TWZLA_STR-VKORG sy-vline 
WA_TWZLA_STR-VTWEG sy-vline 
WA_TWZLA_STR-WERKS sy-vline 
WA_TWZLA_STR-KUNNR sy-vline 
WA_TWZLA_STR-STRNR sy-vline 
WA_TWZLA_STR-KZKSN sy-vline 
WA_TWZLA_STR-KZPCN sy-vline 
WA_TWZLA_STR-RPLFL sy-vline      INTO ld_text SEPARATED BY SPACE.

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