I want to backup my database when a changes happen in my system,like for example i add new user/ update/ delete etc. I want to know wether it is possible or not?I'm not a pro user of vb.net that's why everything is still new to me :)
Yes it is possible but how depends on what database you are using and where you plan to place the backup.
If it is a file based database like Access then simple file copying procedures would work. If the Access database is local you could even make use of the File System Watcher so that you are notified of when a change happens and you can then process your routine to copy the database.
If it is SQL Server you could make use of SMO (SQL Server Management Objects) to do the backup.
so one of the disadvantage of backup automatically is run out of space right, but in my system Ordering System, i want to back up database because of Sales,its my first time to backup, through research my codes works ok, s now i try to bacup it automatically, should use timer? like every end of the day ,it will backup automatically/?
Size is certainly a factor but then it depends on how often and how many backups you will make. It also depends on how big your database is or will become.
What database are you using?
If you want to backup at the end of each day then a backup process should be in place to do this for you. How you implement this really depends on my question. Also, I would not encourage you to write the backup routine yourself but instead use tools available to you in your environment. For example, if this database is on a server, does the server get backed up? If it does then your database could be included within this. If your database is local to your machine then you could create a scheduled task to back up a database that is file based or an SQL Server job to do the backup if it is SQL Server based.
For Access just copy and paste your database to your destination folder by using FileSystemObject programmatically.
If you use MSSQL or MySQL you must make a procedure to get a backup of your database.