Lesson 4: Adding synchronization scripts

This lesson assumes you have completed all preceding lessons. See Lesson 1: Setting up an Excel worksheet.

In this lesson you add scripts to your consolidated database for SQL row handling and direct row handling.

SQL row handling allows you to synchronize remote data with tables in your MobiLink consolidated database. SQL-based scripts define:

  • How data that is uploaded from a MobiLink client is to be applied to the consolidated database.

  • What data should be downloaded from the consolidated database.

In this lesson, you write synchronization scripts for the following SQL-based upload and download events:

  • upload_insert   This event defines how new orders inserted in a client database should be applied to the consolidated database.

  • download_cursor   This event defines the orders that should be downloaded to remote clients.

  • download_delete_cursor   This event is required when using synchronization scripts that are not upload-only. You set the MobiLink server to ignore this event for the purpose of this tutorial.

You use direct row handling to add special processing to a SQL-based synchronization system. In this procedure you register method names corresponding to the handle_UploadData, handle_DownloadData, download_cursor, and download_delete_cursor events. You create your own Java class in a later lesson.

 Add scripts to your consolidated database for SQL row handling and direct row handling

  1. Connect to your consolidated database from Interactive SQL if you are not already connected.

    Run the following command:

    dbisql -c "DSN=mlexcel_db"

  2. Use the ml_add_table_script stored procedure to add SQL-based table scripts for the upload_insert, download_cursor and download_delete_cursor events.

    Execute the following SQL statements in Interactive SQL. The upload_insert script inserts the uploaded order_id, product_id, quantity, and order_status into the MobiLink consolidated database. The download_cursor script uses timestamp-based filtering to download updated rows to remote clients. 



    CALL ml_add_table_script( 'default', 'RemoteOrders', 
    'upload_insert',
    'INSERT INTO RemoteOrders( order_id, product_id, quantity, order_status)
    VALUES( {ml r.order_id}, {ml r.product_id}, {ml r.quantity}, {ml r.order_status} )' );
   
CALL ml_add_table_script( 'default', 'RemoteOrders',
    'download_cursor',
    'SELECT order_id, product_id, quantity, order_status
    FROM RemoteOrders WHERE last_modified >= {ml s.last_table_download}');

CALL ml_add_table_script( 'default', 'RemoteOrders',
    'download_delete_cursor', '--{ml_ignore}');

COMMIT

  3. Register Java methods for the handle_UploadData and handle_DownloadData events.

    Execute the following SQL statements in Interactive SQL:

    CALL ml_add_java_connection_script( 'default', 
    'handle_UploadData',
    'MobiLinkOrders.GetUpload' );
   
CALL ml_add_java_connection_script( 'default',
    'handle_DownloadData',
    'MobiLinkOrders.SetDownload' );

    Interactive SQL registers the GetUpload and SetDownload methods for the handle_UploadData and handle_DownloadData events, respectively. You create these methods in an upcoming lesson.

  4. Register the download_cursor and download_delete_cursor events.

    Run the following SQL script in Interactive SQL:

    CALL ml_add_table_script( 'default', 'OrderComments',
    'download_cursor', '--{ml_ignore}');

CALL ml_add_table_script( 'default', 'OrderComments',
    'download_delete_cursor', '--{ml_ignore}');

    The download_cursor and download_delete_cursor events must be registered for the OrderComments table when using scripts because the synchronization is bi-directional and not upload-only. See Required scripts.

  5. Commit your changes.

    Execute the following SQL statement in Interactive SQL:

    COMMIT;

  6. Proceed to Lesson 5: Creating a Java class for MobiLink direct row handling.

 See also
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