What is currently the best free SQL database engine (with built-in data security/encryption) that can be used to develop standalone Windows desktop applications?
I want to create a simple Windows desktop application in C# for Invoicing. Users will have the option to connect to remotely hosted MySQL servers or to run fully standalone/offline. Hence the need to embed a database engine.
I have considered but ruled out SQLite because it does not have built-in security and because it does not support the complete set of ALTER TABLE features that I am likely to need for future application updates. e.g. ALTER COLUMN, ADD CONSTRAINT, and others are not supported.
Microsoft's SQL Server Compact would have been good for what I need, but it was depreciated many years ago and support actually ended this month.