Why can't you downgrade an apk without deleting the current version?

Question

Android

Good afternoon. Guys, can someone explain in 2 words why it is impossible to install an application with an apk version lower than the one that is already installed? Thank you.

Answer 1

In general, the correct answer would be rather that the Android system checks the apk manifest file and, if the package (application identifier in the system) is the same, and the version code (internal version number) is lower than the existing one, then the system will not let you install this application.

Answer 2

Because nobody wants it.
If in more than a nutshell, then in new versions of the software there may be a different scheme for interacting with data, for example, changing the structure of the config or database. When you rollback, the application may simply crash.

Answer 3

In a nutshell - the Android system forbids this. Everything else is philosophy. If it was allowed, and there was an API for it, then it would be possible.

Answer 4

The concept of "migration".
https://www.yiiframework.com/doc/guide/2.0/en/db-m...
Theoretically, besides up() there should be down()
But even in this case, rollback should be done from the new version.
The previous version of the program does not know about innovations.
And then there are the rules of the game. DO NOT install code from your servers.
And after launching a new release into production, there is no way to download the previous release from the play.
And if there is no way to automatically get the old assembly, then no one writes back migrations.