Backups – Xojo Programming Blog https://blog.xojo.com Blog about the Xojo programming language and IDE Tue, 09 Mar 2021 16:54:18 +0000 en-US hourly 1 https://wordpress.org/?v=6.9.4 Backwards SQLite Backups https://blog.xojo.com/2021/03/09/backwards-sqlite-backups/ Tue, 09 Mar 2021 16:54:16 +0000 https://blog.xojo.com/?p=8121 If you use SQLite databases in your apps you may or may not be aware of the Backup method which allows you to quickly and asynchronously create a backup of an existing connected database. This is especially great if you have an in-memory database and you want to store that data on disk for later reference. I am using the simpler synchronous calls for this example:

memoryDB.Backup(fileDB, Nil, -1) 

Something that’s often overlooked is that you can use the Backup method to go the other way… that is, it can be used to load a disk-based database back into memory by simply swapping the parameters:

// Connect to the database file on disk
Var fileDB as New SQLiteDatabase
fileDB.DatabaseFile = SpecialFolder.Resources.Child("template.db")
fileDB.Connect

// Create the database in memory
Var memoryDB as New SQLiteDatabase
memoryDB.Connect

// "Backup" the file database into memory
fileDB.Backup(memoryDB, Nil, -1)

// Close the file database
fileDB.Close

And voila! You’ve restored the database back into memory!

For more information about this command, please see SQLiteDatabase.Backup on https://documentation.xojo.com.

]]>