select-data-and-write-it-to-archive-files-f24d613.md

Select Data and Write It to Archive Files

The runtime to write archived data to an external storage should be implemented in a central ABAP class. This ABAP class must register the interface IF_ARCH_WRITE to be able to be selected in an archiving object definition in ADT. This ABAP class can be performed within an application job.

The purpose of the ABAP class is the selection of application data which will be archived from the database. By using the ADK write API, this application data can be handed over to create a data object. A data object can contain entries of different tables that have been listed in the definition of the archiving object in ADT. Typically, these are all tables belonging to one business object instance, but there is no technical restriction. The application is free to group the tables according to their needs.

As soon as the data object is completed, the object will be transferred as an archiving file to the related storage manager implementation to store data in the related external storage.

The following table shows the write API to collect the data that will be archived:

CL_ARCH_WRITE_API
Method	Parameter	Description
GET_INSTANCE Static method which returns an instance of the write API via parameter RO_WRITE_INSTANCE	Importing: IV_ARCHIVING_OBJECT	Name of the archiving object which will be used
	Importing:IV_TESTMODE	True: no storage takes place False: Archive content is written, and storage is requested
	Returning:RO_WRITE_INSTANCE	Instance of the write API for further processing

The following table shows the interface for writing archived data:

IF_ARCH_WRITE_API
Method	Parameter	Description
OPEN_DATA_OBJECT Opens a new data object for the data of the business object instance
PUT_DATA_RECORDS Writes the data for a specific table to the open data object	Importing:IV_TABLE_NAME	Name of the table which will be archived
	Importing:IT_RECORDS	Records of the table
CLOSE_DATA_OBJECT Closes the data object and writes it to the archive file	Exporting:EV_OBJECT_OFFSET	Offset at which the data of the data object starts (can be used to build application owned indices for the archived data)
	Exporting:EV_ARCHIVE_KEY	Archive key of the archive file to which the data was written (can be used to build application owned indices for the archived data)
	Exporting:EV_ARCHIVING_SESSION	Sessions of the archiving object to be used
FINALIZE Finalizes processing and closes the archiving session

Typical flow of the archiving write process:

1. Create an instance of the write API and open the archiving write session by using method CL_ARCH_WRITE_API=>GET_INSTANCE.

2. Select the data from your application DB tables.

3. For each data object you want to archive, call method OPEN_DATA_OBJECT.

4. For each table you want to archive entries from, call method PUT_DATA_RECORDS.

5. As soon as all tables of your data object are passed to the API, call method CLOSE_DATA_OBJECT.

6. Either start with the next data object (step 3) or finish the archiving write session by calling method FINALIZE.

Sample Code:

CONSTANTS: lc_object TYPE sarch_object VALUE ‘MY_OBJECT’. 
" Replace with the name of your ADT archiving object
" select flight data (leading table) from the database (replace table names with your names of your own tables)
        SELECT * FROM my_header_table
                 WHERE carrid     IN @lt_range_carrid
                   AND connid     IN @lt_range_connid
                   AND fldate     IN @lt_range_fldate
          INTO TABLE @DATA(lt_flights).
        " open a new archiving session to archive data
        TRY.
            DATA(lo_write) = cl_arch_write_api=>get_instance( iv_archiving_object = lc_object 								  iv_testmode = lv_test ).

            LOOP AT lt_flights ASSIGNING FIELD-SYMBOL(<ls_flight>).
 " select data of dependent tables (replace table names with your names of your own tables)
              INSERT <ls_flight> INTO lt_flights.
              SELECT * FROM my_item_table1
                 WHERE carrid     = @<ls_flight>-carrid
                   AND connid     = @<ls_flight>-connid
                   AND fldate     = @<ls_flight>-fldate
               INTO TABLE @DATA(lt_bookings).
              SELECT * FROM my_item_table2
                 WHERE carrid     = @<ls_flight>-carrid
                   AND connid     = @<ls_flight>-connid
                   AND fldate     = @<ls_flight>-fldate
               INTO TABLE @DATA(lt_tickets).
              SELECT * FROM my_item_table3
                 WHERE carrid     = @<ls_flight>-carrid
                   AND connid     = @<ls_flight>-connid
                   AND fldate     = @<ls_flight>-fldate
               INTO TABLE @DATA(lt_invoices).

              " open new ADK data object
              lo_write->open_data_object( ).

              " write data of header table
              lo_write->put_data_records( iv_table_name = ‘<MY_HEADER_TALBE>’ it_records = lt_sflight_arch ).
              CLEAR lt_sflight_arch.

              " write data of depending tables
              lo_write->put_data_records( iv_table_name = ‘<MY_ITEM_TABLE1>’ it_records = lt_bookings ). " bookings
              CLEAR lt_sflight_arch.
              Lo_write->put_data_records( iv_table_name = ‘<MY_ITEM_TABLE2>’ it_records = lt_tickets ). " tickets
              CLEAR lt_sflight_arch.
              Lo_write->put_data_records( iv_table_name = ‘<MY_ITEM_TABLE3>’ it_records = lt_invoices ). " invoices
              CLEAR lt_sflight_arch.

              " write data object into the archive file
              lo_write->close_data_object( ).

            ENDLOOP.

            " finalize and end writing
            lo_write->finalize( ).