Embedded SQL programming techniques

This section contains a set of tips for developers of embedded SQL programs.

Implementing request management

The default behavior of the interface DLL is for applications to wait for completion of each database request before carrying out other functions. This behavior can be changed using request management functions. For example, when using Interactive SQL, the operating system is still active while Interactive SQL is waiting for a response from the database and Interactive SQL carries out some tasks in that time.

You can achieve application activity while a database request is in progress by providing a callback function. In this callback function, you must not do another database request except db_cancel_request. You can use the db_is_working function in your message handlers to determine if you have a database request in progress.

The db_register_a_callback function is used to register your application callback functions.

Backup functions

The db_backup function provides support for online backup in embedded SQL applications. The backup utility makes use of this function. You should only need to write a program to use this function if your backup requirements are not satisfied by the SQL Anywhere backup utility.

BACKUP statement is recommended

Although this function provides one way to add backup features to an application, the recommended way to do this task is to use the BACKUP statement. See BACKUP statement.

You can also access the backup utility directly using the Database Tools DBBackup function. See DBBackup function.