ABAP Select data from SAP table ALCOMP into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM ALCOMP
*  INTO TABLE @DATA(IT_ALCOMP2).
*--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_ALCOMP INDEX 1 INTO DATA(WA_ALCOMP2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<ALCOMP>-CONTREP = 1.
<ALCOMP>-ARC_DOC_ID = 1.
<ALCOMP>-DOC_TYPE = 1.
<ALCOMP>-COMPID = 1.
<ALCOMP>-MIMETYPE = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_ALCOMP-COMPSIZE, sy-vline,
  WA_ALCOMP-ROOTOBJECT, sy-vline,
  WA_ALCOMP-COMPDATEC, sy-vline,
  WA_ALCOMP-COMPTIMEC, sy-vline,
  WA_ALCOMP-COMPDATEM, sy-vline,
  WA_ALCOMP-COMPTIMEM, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_ALCOMP 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_ALCOMP 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_ALCOMP INTO WA_ALCOMP.


*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_ALCOMP_STR, 
CONTREP TYPE STRING,
ARC_DOC_ID TYPE STRING,
DOC_TYPE TYPE STRING,
COMPID TYPE STRING,
MIMETYPE TYPE STRING,
COMPSIZE TYPE STRING,
ROOTOBJECT TYPE STRING,
COMPDATEC TYPE STRING,
COMPTIMEC TYPE STRING,
COMPDATEM TYPE STRING,
COMPTIMEM TYPE STRING,
STATUS TYPE STRING,END OF T_EKKO_STR.
DATA: WA_ALCOMP_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_ALCOMP_STR-CONTREP sy-vline 
WA_ALCOMP_STR-ARC_DOC_ID sy-vline 
WA_ALCOMP_STR-DOC_TYPE sy-vline 
WA_ALCOMP_STR-COMPID sy-vline 
WA_ALCOMP_STR-MIMETYPE sy-vline 
WA_ALCOMP_STR-COMPSIZE sy-vline 
WA_ALCOMP_STR-ROOTOBJECT sy-vline 
WA_ALCOMP_STR-COMPDATEC sy-vline 
WA_ALCOMP_STR-COMPTIMEC sy-vline 
WA_ALCOMP_STR-COMPDATEM sy-vline 
WA_ALCOMP_STR-COMPTIMEM sy-vline 
WA_ALCOMP_STR-STATUS sy-vline      INTO ld_text SEPARATED BY SPACE.

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