ABAP Select data from SAP table MDG_DT_API_MODEL_TABLE into internal table

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

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

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

*Select data and declare internal table using in-line method @DATA
*SELECT *
*  FROM MDG_DT_API_MODEL_TABLE
*  INTO TABLE @DATA(IT_MDG_DT_API_MODEL_TABLE2).
*--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_MDG_DT_API_MODEL_TABLE INDEX 1 INTO DATA(WA_MDG_DT_API_MODEL_TABLE2).


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

*To update a field value using a field symbol simply change the value via the field symbol pointer
<MDG_DT_API_MODEL_TABLE>-MODELHEADER = 1.
<MDG_DT_API_MODEL_TABLE>-MODEL_NAME = 1.
<MDG_DT_API_MODEL_TABLE>-USER_NAME = 1.
<MDG_DT_API_MODEL_TABLE>-CHANGED_ON = 1.
<MDG_DT_API_MODEL_TABLE>-LAST_CHANGED_AT = 1.

ENDLOOP.

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

*Write selected data to screen/report before conversion.
  WRITE:/ sy-vline,   WA_MDG_DT_API_MODEL_TABLE-REUSE_ACT_AREA, sy-vline,
  WA_MDG_DT_API_MODEL_TABLE-DESCRIPTION, sy-vline,
  WA_MDG_DT_API_MODEL_TABLE-MODEL_STATUS, sy-vline,
  WA_MDG_DT_API_MODEL_TABLE-NAMESPACE, sy-vline,
  WA_MDG_DT_API_MODEL_TABLE-DEVCLASS, sy-vline,
  WA_MDG_DT_API_MODEL_TABLE-NAMESPACE_CI, sy-vline.
ENDLOOP.
   
*Add any further fields from structure WA_MDG_DT_API_MODEL_TABLE 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_MDG_DT_API_MODEL_TABLE 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_MDG_DT_API_MODEL_TABLE INTO WA_MDG_DT_API_MODEL_TABLE.


*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_MDG_DT_API_MODEL_TABLE_STR, 
MODELHEADER TYPE STRING,
MODEL_NAME TYPE STRING,
USER_NAME TYPE STRING,
CHANGED_ON TYPE STRING,
LAST_CHANGED_AT TYPE STRING,
REUSE_ACT_AREA TYPE STRING,
DESCRIPTION TYPE STRING,
MODEL_STATUS TYPE STRING,
NAMESPACE TYPE STRING,
DEVCLASS TYPE STRING,
NAMESPACE_CI TYPE STRING,
DEVCLASS_CI TYPE STRING,
ENTITIES TYPE STRING,
ATTRIBUTES TYPE STRING,
RELATIONSHIPS TYPE STRING,
REUSE_ACTIVE_AREA TYPE STRING,
HIERARCHY TYPE STRING,
HIERARCHY_ATTRIBUTE TYPE STRING,
HIERARCHY_RELATIONSHIP TYPE STRING,
BO_TYPE TYPE STRING,END OF T_EKKO_STR.
DATA: WA_MDG_DT_API_MODEL_TABLE_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_MDG_DT_API_MODEL_TABLE_STR-MODELHEADER sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-MODEL_NAME sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-USER_NAME sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-CHANGED_ON sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-LAST_CHANGED_AT sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-REUSE_ACT_AREA sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-DESCRIPTION sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-MODEL_STATUS sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-NAMESPACE sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-DEVCLASS sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-NAMESPACE_CI sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-DEVCLASS_CI sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-ENTITIES sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-ATTRIBUTES sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-RELATIONSHIPS sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-REUSE_ACTIVE_AREA sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-HIERARCHY sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-HIERARCHY_ATTRIBUTE sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-HIERARCHY_RELATIONSHIP sy-vline 
WA_MDG_DT_API_MODEL_TABLE_STR-BO_TYPE sy-vline      INTO ld_text SEPARATED BY SPACE.

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