ABAP Select data from SAP table WCAIT into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM WCAIT
*  INTO TABLE @DATA(IT_WCAIT2).
*--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_WCAIT INDEX 1 INTO DATA(WA_WCAIT2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<WCAIT>-MANDT = 1.
<WCAIT>-WCNR = 1.
<WCAIT>-WCITM = 1.
<WCAIT>-OBJNR = 1.
<WCAIT>-ITMTYP = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_WCAIT-SEQ, sy-vline,
  WA_WCAIT-PRED, sy-vline,
  WA_WCAIT-SUCC, sy-vline,
  WA_WCAIT-CCOBJ, sy-vline,
  WA_WCAIT-CCTYP, sy-vline,
  WA_WCAIT-STXT, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_WCAIT 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_WCAIT 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_WCAIT INTO WA_WCAIT.


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

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

*Conversion exit ALPHA, internal->external for field UNNR
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_OUTPUT'
  EXPORTING
    input =                      WA_WCAIT-UNNR
  IMPORTING
    output =                     ld_input.
WRITE:/ 'Org Value:', WA_WCAIT-UNNR.
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_WCAIT_STR, 
MANDT TYPE STRING,
WCNR TYPE STRING,
WCITM TYPE STRING,
OBJNR TYPE STRING,
ITMTYP TYPE STRING,
SEQ TYPE STRING,
PRED TYPE STRING,
SUCC TYPE STRING,
CCOBJ TYPE STRING,
CCTYP TYPE STRING,
STXT TYPE STRING,
TGGRP TYPE STRING,
TGSTEP TYPE STRING,
TGPROC TYPE STRING,
TGTYP TYPE STRING,
TGSEQ TYPE STRING,
TGTXT TYPE STRING,
UNSTEP TYPE STRING,
UNPROC TYPE STRING,
UNTYP TYPE STRING,
UNSEQ TYPE STRING,
UNTXT TYPE STRING,
PHBLFLG TYPE STRING,
PHBLTYP TYPE STRING,
PHBLNR TYPE STRING,
TGFLG TYPE STRING,
TGFORM TYPE STRING,
TGNR TYPE STRING,
UNFORM TYPE STRING,
UNNR TYPE STRING,
CONTROL TYPE STRING,
LOCATION TYPE STRING,
LFLG TYPE STRING,
DOCFLG TYPE STRING,
REFOBJ TYPE STRING,END OF T_EKKO_STR.
DATA: WA_WCAIT_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_WCAIT_STR-MANDT sy-vline 
WA_WCAIT_STR-WCNR sy-vline 
WA_WCAIT_STR-WCITM sy-vline 
WA_WCAIT_STR-OBJNR sy-vline 
WA_WCAIT_STR-ITMTYP sy-vline 
WA_WCAIT_STR-SEQ sy-vline 
WA_WCAIT_STR-PRED sy-vline 
WA_WCAIT_STR-SUCC sy-vline 
WA_WCAIT_STR-CCOBJ sy-vline 
WA_WCAIT_STR-CCTYP sy-vline 
WA_WCAIT_STR-STXT sy-vline 
WA_WCAIT_STR-TGGRP sy-vline 
WA_WCAIT_STR-TGSTEP sy-vline 
WA_WCAIT_STR-TGPROC sy-vline 
WA_WCAIT_STR-TGTYP sy-vline 
WA_WCAIT_STR-TGSEQ sy-vline 
WA_WCAIT_STR-TGTXT sy-vline 
WA_WCAIT_STR-UNSTEP sy-vline 
WA_WCAIT_STR-UNPROC sy-vline 
WA_WCAIT_STR-UNTYP sy-vline 
WA_WCAIT_STR-UNSEQ sy-vline 
WA_WCAIT_STR-UNTXT sy-vline 
WA_WCAIT_STR-PHBLFLG sy-vline 
WA_WCAIT_STR-PHBLTYP sy-vline 
WA_WCAIT_STR-PHBLNR sy-vline 
WA_WCAIT_STR-TGFLG sy-vline 
WA_WCAIT_STR-TGFORM sy-vline 
WA_WCAIT_STR-TGNR sy-vline 
WA_WCAIT_STR-UNFORM sy-vline 
WA_WCAIT_STR-UNNR sy-vline 
WA_WCAIT_STR-CONTROL sy-vline 
WA_WCAIT_STR-LOCATION sy-vline 
WA_WCAIT_STR-LFLG sy-vline 
WA_WCAIT_STR-DOCFLG sy-vline 
WA_WCAIT_STR-REFOBJ sy-vline      INTO ld_text SEPARATED BY SPACE.

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