If an error occurs during startup before a synchronization has been initiated, the #hook_dict entries for MobiLink user and Script version are set to an empty string, and no publication_n or subscription_n rows are set in the #hook_dict table.

The error hook user state row provides a useful mechanism for you to pass information about the nature of the error to the sp_hook_dbmlsync_end hook where you might use that information to decide whether to retry the synchronization.

This procedure executes on a separate connection to ensure that operations it performs are not lost if a rollback is performed on the synchronization connection. If dbmlsync cannot establish a separate connection, the procedure is not called.

Since this hook executes on a separate connection you should use care when accessing tables that are being synchronized in your hook procedure because dbmlsync may have locks on these tables. These locks could cause operations in your hook to fail or to wait indefinitely.

Actions of this procedure are committed immediately after execution.

• Handling errors and warnings in event hook procedures
• sp_hook_dbmlsync_communication_error
• sp_hook_dbmlsync_all_error
• sp_hook_dbmlsync_sql_error

Assume you use the following table to log errors in the remote database.

CREATE TABLE error_log
(
 pk INTEGER DEFAULT AUTOINCREMENT PRIMARY KEY,
 err_id INTEGER,
 err_msg VARCHAR(10240),
);

The following example sets up sp_hook_dbmlsync_misc_error to log all types of error messages.

CREATE PROCEDURE sp_hook_dbmlsync_misc_error()
BEGIN
 DECLARE msg VARCHAR(10240);
 DECLARE id INTEGER;

 // get the error message text
 SELECT value INTO msg
  FROM #hook_dict
  WHERE name ='error message';

 // get the error id
 SELECT value INTO id
  FROM #hook_dict
  WHERE name = 'error id';

 // log the error information
 INSERT INTO error_log(err_msg,err_id)
  VALUES (msg,id);
END;

To see possible error id values, test run dbmlsync. For example, the following dbmlsync command line references an invalid subscription.

dbmlsync -c server=custdb;uid=DBA;pwd=sql -s test

Now, the error_log table contains the following row, associating the error with the error id 9931.

1,19912,
 'Subscription ''test'' not found.'

To provide custom error handling, check for the error id 19912 in sp_hook_dbmlsync_misc_error.

ALTER PROCEDURE sp_hook_dbmlsync_misc_error()
BEGIN
 DECLARE msg VARCHAR(10240);
 DECLARE id INTEGER;

 // get the error message text
 SELECT value INTO msg
  FROM #hook_dict
  WHERE name ='error message';

 // get the error id
 SELECT value INTO id
  FROM #hook_dict
  WHERE name = 'error id';

 // log the error information
 INSERT INTO error_log(err_msg,err_id)
  VALUES (msg,id);

 IF id = 19912 THEN
  // handle invalid subscription
 END IF;

END;