ABAP Select data from SAP table TN1FORMLEVEL into internal table

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Below is a number of ABAP code snippets to demonstrate how to select data from SAP TN1FORMLEVEL 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 TN1FORMLEVEL. 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 TN1FORMLEVEL 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_TN1FORMLEVEL TYPE STANDARD TABLE OF TN1FORMLEVEL,
      WA_TN1FORMLEVEL TYPE TN1FORMLEVEL,
      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: <TN1FORMLEVEL> TYPE TN1FORMLEVEL.

*Process all fields in table header/work area as string values
  PERFORM process_as_string_field_values CHANGING wa_TN1FORMLEVEL.

SELECT *
*restrict ABAP select to first 10 rows
 UP TO 10 ROWS      
  FROM TN1FORMLEVEL
  INTO TABLE IT_TN1FORMLEVEL.

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM TN1FORMLEVEL
*  INTO TABLE @DATA(IT_TN1FORMLEVEL2).
*--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_TN1FORMLEVEL INDEX 1 INTO DATA(WA_TN1FORMLEVEL2).


*Demonstrate how to loop at an internal table and update values using a FIELD-SYMBOL
LOOP AT IT_TN1FORMLEVEL ASSIGNING <TN1FORMLEVEL>.

*To update a field value using a field symbol simply change the value via the field symbol pointer
<TN1FORMLEVEL>-MANDT = 1.
<TN1FORMLEVEL>-FORMLVL = 1.
<TN1FORMLEVEL>-CATID = 1.
<TN1FORMLEVEL>-LVLTYP = 1.
<TN1FORMLEVEL>-EMAR = 1.

ENDLOOP.

LOOP AT IT_TN1FORMLEVEL INTO WA_TN1FORMLEVEL.
*Write horizonal line to screen report.
  WRITE:/ sy-uline.

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_TN1FORMLEVEL-DISP, sy-vline,
  WA_TN1FORMLEVEL-PPRINT, sy-vline,
  WA_TN1FORMLEVEL-DLEMAR, sy-vline,
  WA_TN1FORMLEVEL-DLDISP, sy-vline,
  WA_TN1FORMLEVEL-DLPPRINT, sy-vline,
  WA_TN1FORMLEVEL-MMACT, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_TN1FORMLEVEL 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_TN1FORMLEVEL 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_TN1FORMLEVEL INTO WA_TN1FORMLEVEL.


*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_TN1FORMLEVEL_STR, 
MANDT TYPE STRING,
FORMLVL TYPE STRING,
CATID TYPE STRING,
LVLTYP TYPE STRING,
EMAR TYPE STRING,
DISP TYPE STRING,
PPRINT TYPE STRING,
DLEMAR TYPE STRING,
DLDISP TYPE STRING,
DLPPRINT TYPE STRING,
MMACT TYPE STRING,
DOCLVL TYPE STRING,
ERDAT TYPE STRING,
ERTIM TYPE STRING,
ERUSR TYPE STRING,
UPDAT TYPE STRING,
UPTIM TYPE STRING,
UPUSR TYPE STRING,
LOEKZ TYPE STRING,
LOUSR TYPE STRING,
LODAT TYPE STRING,
LOTIM TYPE STRING,
DLANAMN TYPE STRING,END OF T_EKKO_STR.
DATA: WA_TN1FORMLEVEL_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_TN1FORMLEVEL_STR-MANDT sy-vline 
WA_TN1FORMLEVEL_STR-FORMLVL sy-vline 
WA_TN1FORMLEVEL_STR-CATID sy-vline 
WA_TN1FORMLEVEL_STR-LVLTYP sy-vline 
WA_TN1FORMLEVEL_STR-EMAR sy-vline 
WA_TN1FORMLEVEL_STR-DISP sy-vline 
WA_TN1FORMLEVEL_STR-PPRINT sy-vline 
WA_TN1FORMLEVEL_STR-DLEMAR sy-vline 
WA_TN1FORMLEVEL_STR-DLDISP sy-vline 
WA_TN1FORMLEVEL_STR-DLPPRINT sy-vline 
WA_TN1FORMLEVEL_STR-MMACT sy-vline 
WA_TN1FORMLEVEL_STR-DOCLVL sy-vline 
WA_TN1FORMLEVEL_STR-ERDAT sy-vline 
WA_TN1FORMLEVEL_STR-ERTIM sy-vline 
WA_TN1FORMLEVEL_STR-ERUSR sy-vline 
WA_TN1FORMLEVEL_STR-UPDAT sy-vline 
WA_TN1FORMLEVEL_STR-UPTIM sy-vline 
WA_TN1FORMLEVEL_STR-UPUSR sy-vline 
WA_TN1FORMLEVEL_STR-LOEKZ sy-vline 
WA_TN1FORMLEVEL_STR-LOUSR sy-vline 
WA_TN1FORMLEVEL_STR-LODAT sy-vline 
WA_TN1FORMLEVEL_STR-LOTIM sy-vline 
WA_TN1FORMLEVEL_STR-DLANAMN sy-vline      INTO ld_text SEPARATED BY SPACE.

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