ABAP Select data from SAP table CLCLASSES into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM CLCLASSES
*  INTO TABLE @DATA(IT_CLCLASSES2).
*--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_CLCLASSES INDEX 1 INTO DATA(WA_CLCLASSES2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<CLCLASSES>-CLASS = 1.
<CLCLASSES>-CLASS_TYPE = 1.
<CLCLASSES>-STATUS = 1.
<CLCLASSES>-GROUP = 1.
<CLCLASSES>-ORG_AREA = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_CLCLASSES-VAL_FROM, sy-vline,
  WA_CLCLASSES-VAL_TO, sy-vline,
  WA_CLCLASSES-AUTH_MAINT, sy-vline,
  WA_CLCLASSES-AUTH_CLASI, sy-vline,
  WA_CLCLASSES-AUTH_SEL, sy-vline,
  WA_CLCLASSES-CHECK_NO, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_CLCLASSES 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_CLCLASSES 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_CLCLASSES INTO WA_CLCLASSES.


*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 DOCUMENT
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_CLCLASSES-DOCUMENT
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_CLCLASSES-DOCUMENT.
WRITE:/ 'New Value:', ld_input.

*Conversion exit CUNIT, internal->external for field BASE_UNIT
CALL FUNCTION 'CONVERSION_EXIT_CUNIT_OUTPUT'
  EXPORTING
    input =                      WA_CLCLASSES-BASE_UNIT
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_CLCLASSES-BASE_UNIT.
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_CLCLASSES_STR, 
CLASS TYPE STRING,
CLASS_TYPE TYPE STRING,
STATUS TYPE STRING,
GROUP TYPE STRING,
ORG_AREA TYPE STRING,
VAL_FROM TYPE STRING,
VAL_TO TYPE STRING,
AUTH_MAINT TYPE STRING,
AUTH_CLASI TYPE STRING,
AUTH_SEL TYPE STRING,
CHECK_NO TYPE STRING,
CHECK_WARN TYPE STRING,
CHECK_ERRO TYPE STRING,
DOCUMENT TYPE STRING,
DOC_TYPE TYPE STRING,
DOC_PART TYPE STRING,
DOC_VERS TYPE STRING,
STANDARD TYPE STRING,
STAND_NO TYPE STRING,
ISSUE_DATE TYPE STRING,
VERS_DATE TYPE STRING,
VERS_NO TYPE STRING,
CHAR_TABLE TYPE STRING,
BOM_ALLOWD TYPE STRING,
BASE_UNIT TYPE STRING,
RES_ITM_CT TYPE STRING,
ORG_AR_ITM TYPE STRING,
REQ_COMP TYPE STRING,
MULT_SELEC TYPE STRING,
FLDELETE TYPE STRING,
LOCLA TYPE STRING,
KATALOG TYPE STRING,END OF T_EKKO_STR.
DATA: WA_CLCLASSES_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_CLCLASSES_STR-CLASS sy-vline 
WA_CLCLASSES_STR-CLASS_TYPE sy-vline 
WA_CLCLASSES_STR-STATUS sy-vline 
WA_CLCLASSES_STR-GROUP sy-vline 
WA_CLCLASSES_STR-ORG_AREA sy-vline 
WA_CLCLASSES_STR-VAL_FROM sy-vline 
WA_CLCLASSES_STR-VAL_TO sy-vline 
WA_CLCLASSES_STR-AUTH_MAINT sy-vline 
WA_CLCLASSES_STR-AUTH_CLASI sy-vline 
WA_CLCLASSES_STR-AUTH_SEL sy-vline 
WA_CLCLASSES_STR-CHECK_NO sy-vline 
WA_CLCLASSES_STR-CHECK_WARN sy-vline 
WA_CLCLASSES_STR-CHECK_ERRO sy-vline 
WA_CLCLASSES_STR-DOCUMENT sy-vline 
WA_CLCLASSES_STR-DOC_TYPE sy-vline 
WA_CLCLASSES_STR-DOC_PART sy-vline 
WA_CLCLASSES_STR-DOC_VERS sy-vline 
WA_CLCLASSES_STR-STANDARD sy-vline 
WA_CLCLASSES_STR-STAND_NO sy-vline 
WA_CLCLASSES_STR-ISSUE_DATE sy-vline 
WA_CLCLASSES_STR-VERS_DATE sy-vline 
WA_CLCLASSES_STR-VERS_NO sy-vline 
WA_CLCLASSES_STR-CHAR_TABLE sy-vline 
WA_CLCLASSES_STR-BOM_ALLOWD sy-vline 
WA_CLCLASSES_STR-BASE_UNIT sy-vline 
WA_CLCLASSES_STR-RES_ITM_CT sy-vline 
WA_CLCLASSES_STR-ORG_AR_ITM sy-vline 
WA_CLCLASSES_STR-REQ_COMP sy-vline 
WA_CLCLASSES_STR-MULT_SELEC sy-vline 
WA_CLCLASSES_STR-FLDELETE sy-vline 
WA_CLCLASSES_STR-LOCLA sy-vline 
WA_CLCLASSES_STR-KATALOG sy-vline      INTO ld_text SEPARATED BY SPACE.

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