ABAP Select data from SAP table PREL_DB into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM PREL_DB
*  INTO TABLE @DATA(IT_PREL_DB2).
*--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_PREL_DB INDEX 1 INTO DATA(WA_PREL_DB2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<PREL_DB>-MANDT = 1.
<PREL_DB>-PERNR = 1.
<PREL_DB>-SUBTY = 1.
<PREL_DB>-OBJPS = 1.
<PREL_DB>-SPRPS = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_PREL_DB-ENDDA, sy-vline,
  WA_PREL_DB-BEGDA, sy-vline,
  WA_PREL_DB-SEQNR, sy-vline,
  WA_PREL_DB-AEDTM, sy-vline,
  WA_PREL_DB-UNAME, sy-vline,
  WA_PREL_DB-HISTO, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_PREL_DB 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_PREL_DB 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_PREL_DB INTO WA_PREL_DB.


*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_PREL_DB_STR, 
MANDT TYPE STRING,
PERNR TYPE STRING,
SUBTY TYPE STRING,
OBJPS TYPE STRING,
SPRPS TYPE STRING,
ENDDA TYPE STRING,
BEGDA TYPE STRING,
SEQNR TYPE STRING,
AEDTM TYPE STRING,
UNAME TYPE STRING,
HISTO TYPE STRING,
ITXEX TYPE STRING,
REFEX TYPE STRING,
ORDEX TYPE STRING,
ITBLD TYPE STRING,
PREAS TYPE STRING,
FLAG1 TYPE STRING,
FLAG2 TYPE STRING,
FLAG3 TYPE STRING,
FLAG4 TYPE STRING,
RESE1 TYPE STRING,
RESE2 TYPE STRING,
GRPVL TYPE STRING,
DATA1 TYPE STRING,
DATA2 TYPE STRING,
DATA3 TYPE STRING,
DATA4 TYPE STRING,
DATA5 TYPE STRING,
DATA6 TYPE STRING,
DATA7 TYPE STRING,END OF T_EKKO_STR.
DATA: WA_PREL_DB_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_PREL_DB_STR-MANDT sy-vline 
WA_PREL_DB_STR-PERNR sy-vline 
WA_PREL_DB_STR-SUBTY sy-vline 
WA_PREL_DB_STR-OBJPS sy-vline 
WA_PREL_DB_STR-SPRPS sy-vline 
WA_PREL_DB_STR-ENDDA sy-vline 
WA_PREL_DB_STR-BEGDA sy-vline 
WA_PREL_DB_STR-SEQNR sy-vline 
WA_PREL_DB_STR-AEDTM sy-vline 
WA_PREL_DB_STR-UNAME sy-vline 
WA_PREL_DB_STR-HISTO sy-vline 
WA_PREL_DB_STR-ITXEX sy-vline 
WA_PREL_DB_STR-REFEX sy-vline 
WA_PREL_DB_STR-ORDEX sy-vline 
WA_PREL_DB_STR-ITBLD sy-vline 
WA_PREL_DB_STR-PREAS sy-vline 
WA_PREL_DB_STR-FLAG1 sy-vline 
WA_PREL_DB_STR-FLAG2 sy-vline 
WA_PREL_DB_STR-FLAG3 sy-vline 
WA_PREL_DB_STR-FLAG4 sy-vline 
WA_PREL_DB_STR-RESE1 sy-vline 
WA_PREL_DB_STR-RESE2 sy-vline 
WA_PREL_DB_STR-GRPVL sy-vline 
WA_PREL_DB_STR-DATA1 sy-vline 
WA_PREL_DB_STR-DATA2 sy-vline 
WA_PREL_DB_STR-DATA3 sy-vline 
WA_PREL_DB_STR-DATA4 sy-vline 
WA_PREL_DB_STR-DATA5 sy-vline 
WA_PREL_DB_STR-DATA6 sy-vline 
WA_PREL_DB_STR-DATA7 sy-vline      INTO ld_text SEPARATED BY SPACE.

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