Connection events

At the connection level, the sequence of major events is as follows:

begin_connection
   begin_synchronization
      begin_upload
      end_upload
      prepare_for_download
      begin_download
      end_download
   end_synchronization
end_connection

When a synchronization request occurs, the begin_connection event is fired. When all synchronization requests for the current script version have been completed, the end_connection event is fired. Typically you place initialization and cleanup code in the scripts for these events, such as variable declaration and database cleanup.

Apart from begin_connection and end_connection, all of these events take the MobiLink user name stored in the ml_user table in the consolidated database as a parameter. You can use parameters in your scripts by placing question marks where the parameter value should be substituted.

To make scripts in SQL Anywhere databases easier to read, you might declare a variable in the begin_connection script, then set it to the value of ml_username in the begin_synchronization script.

For example, in begin_connection:

CREATE VARIABLE @sync_user VARCHAR(128);

In begin_synchronization:

SET @sync_user = ?

The begin_synchronization and end_synchronization events are fired before and after changes are applied to the remote and consolidated databases.

The begin_upload event marks the beginning of the upload transaction. Applicable inserts and updates to the consolidated database are performed for all remote tables, then rows are deleted as applicable for all remote tables. After end_upload, upload changes are committed.