ABAP Select data from SAP table TREX_RFC into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM TREX_RFC
*  INTO TABLE @DATA(IT_TREX_RFC2).
*--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_TREX_RFC INDEX 1 INTO DATA(WA_TREX_RFC2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<TREX_RFC>-INDEX_ID = 1.
<TREX_RFC>-LANGUAGE = 1.
<TREX_RFC>-DESCRIPTION = 1.
<TREX_RFC>-SEARCH_ENGINE = 1.
<TREX_RFC>-LOCATION = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_TREX_RFC-FLAG, sy-vline,
  WA_TREX_RFC-RCODE, sy-vline,
  WA_TREX_RFC-RFC_DESTINATION, sy-vline,
  WA_TREX_RFC-NUMC, sy-vline,
  WA_TREX_RFC-RETURN_CODE, sy-vline,
  WA_TREX_RFC-RETURN_TEXT, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_TREX_RFC 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_TREX_RFC 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_TREX_RFC INTO WA_TREX_RFC.


*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_TREX_RFC_STR, 
INDEX_ID TYPE STRING,
LANGUAGE TYPE STRING,
DESCRIPTION TYPE STRING,
SEARCH_ENGINE TYPE STRING,
LOCATION TYPE STRING,
FLAG TYPE STRING,
RCODE TYPE STRING,
RFC_DESTINATION TYPE STRING,
NUMC TYPE STRING,
RETURN_CODE TYPE STRING,
RETURN_TEXT TYPE STRING,
CLASSIFY_ATTR TYPE STRING,
CLASSIFY_METHOD TYPE STRING,
CLASSIFY_TYPE TYPE STRING,
DOC_SEL_QUERY TYPE STRING,
RES_TERM_PAT TYPE STRING,
REQUEST_FLAG TYPE STRING,
REQUEST_FLAG_L TYPE STRING,
REQUEST_CONTENT TYPE STRING,
TERM_NAME TYPE STRING,
TERM_ID TYPE STRING,
TERM_WEIGHT TYPE STRING,
TAXONOMY_NAME TYPE STRING,
NAMESPACE TYPE STRING,
ATTRIBUTE TYPE STRING,
CLUSTERING_METHOD TYPE STRING,
DOC_SIM_METHOD TYPE STRING,
REQUESTED_RESULTS TYPE STRING,
QUEUE_ENTRY_CHOICE TYPE STRING,
RETRY_COUNT TYPE STRING,
DOC_STATE TYPE STRING,
FAILED_TYPE TYPE STRING,
MAX_RESULTS TYPE STRING,
TOPOLOGY_PATH TYPE STRING,
MODIFY_ACTION TYPE STRING,
BOOLEAN TYPE STRING,
PATH TYPE STRING,
VALUE TYPE STRING,
HOST TYPE STRING,
SERVICE TYPE STRING,
SEPARATOR TYPE STRING,
TIME_STAMP TYPE STRING,
NUMC3 TYPE STRING,
ICON TYPE STRING,
QUERY_ID TYPE STRING,
NUMC10 TYPE STRING,
NUMC16 TYPE STRING,
TOP_TYPE TYPE STRING,
TOP_VALUE TYPE STRING,
ANALYZER_TYPE TYPE STRING,
LOCATION2 TYPE STRING,
BOOLEAN_OPERATOR TYPE STRING,
LOCALE TYPE STRING,
FUNCTION_NAME TYPE STRING,
LLONG TYPE STRING,END OF T_EKKO_STR.
DATA: WA_TREX_RFC_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_TREX_RFC_STR-INDEX_ID sy-vline 
WA_TREX_RFC_STR-LANGUAGE sy-vline 
WA_TREX_RFC_STR-DESCRIPTION sy-vline 
WA_TREX_RFC_STR-SEARCH_ENGINE sy-vline 
WA_TREX_RFC_STR-LOCATION sy-vline 
WA_TREX_RFC_STR-FLAG sy-vline 
WA_TREX_RFC_STR-RCODE sy-vline 
WA_TREX_RFC_STR-RFC_DESTINATION sy-vline 
WA_TREX_RFC_STR-NUMC sy-vline 
WA_TREX_RFC_STR-RETURN_CODE sy-vline 
WA_TREX_RFC_STR-RETURN_TEXT sy-vline 
WA_TREX_RFC_STR-CLASSIFY_ATTR sy-vline 
WA_TREX_RFC_STR-CLASSIFY_METHOD sy-vline 
WA_TREX_RFC_STR-CLASSIFY_TYPE sy-vline 
WA_TREX_RFC_STR-DOC_SEL_QUERY sy-vline 
WA_TREX_RFC_STR-RES_TERM_PAT sy-vline 
WA_TREX_RFC_STR-REQUEST_FLAG sy-vline 
WA_TREX_RFC_STR-REQUEST_FLAG_L sy-vline 
WA_TREX_RFC_STR-REQUEST_CONTENT sy-vline 
WA_TREX_RFC_STR-TERM_NAME sy-vline 
WA_TREX_RFC_STR-TERM_ID sy-vline 
WA_TREX_RFC_STR-TERM_WEIGHT sy-vline 
WA_TREX_RFC_STR-TAXONOMY_NAME sy-vline 
WA_TREX_RFC_STR-NAMESPACE sy-vline 
WA_TREX_RFC_STR-ATTRIBUTE sy-vline 
WA_TREX_RFC_STR-CLUSTERING_METHOD sy-vline 
WA_TREX_RFC_STR-DOC_SIM_METHOD sy-vline 
WA_TREX_RFC_STR-REQUESTED_RESULTS sy-vline 
WA_TREX_RFC_STR-QUEUE_ENTRY_CHOICE sy-vline 
WA_TREX_RFC_STR-RETRY_COUNT sy-vline 
WA_TREX_RFC_STR-DOC_STATE sy-vline 
WA_TREX_RFC_STR-FAILED_TYPE sy-vline 
WA_TREX_RFC_STR-MAX_RESULTS sy-vline 
WA_TREX_RFC_STR-TOPOLOGY_PATH sy-vline 
WA_TREX_RFC_STR-MODIFY_ACTION sy-vline 
WA_TREX_RFC_STR-BOOLEAN sy-vline 
WA_TREX_RFC_STR-PATH sy-vline 
WA_TREX_RFC_STR-VALUE sy-vline 
WA_TREX_RFC_STR-HOST sy-vline 
WA_TREX_RFC_STR-SERVICE sy-vline 
WA_TREX_RFC_STR-SEPARATOR sy-vline 
WA_TREX_RFC_STR-TIME_STAMP sy-vline 
WA_TREX_RFC_STR-NUMC3 sy-vline 
WA_TREX_RFC_STR-ICON sy-vline 
WA_TREX_RFC_STR-QUERY_ID sy-vline 
WA_TREX_RFC_STR-NUMC10 sy-vline 
WA_TREX_RFC_STR-NUMC16 sy-vline 
WA_TREX_RFC_STR-TOP_TYPE sy-vline 
WA_TREX_RFC_STR-TOP_VALUE sy-vline 
WA_TREX_RFC_STR-ANALYZER_TYPE sy-vline 
WA_TREX_RFC_STR-LOCATION2 sy-vline 
WA_TREX_RFC_STR-BOOLEAN_OPERATOR sy-vline 
WA_TREX_RFC_STR-LOCALE sy-vline 
WA_TREX_RFC_STR-FUNCTION_NAME sy-vline 
WA_TREX_RFC_STR-LLONG sy-vline      INTO ld_text SEPARATED BY SPACE.

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