Preserving some tables when upgrading app database?

In my sqlite3 database I have some tables with user added values that开发者_运维百科 I would like to preserve when I upgrade my app. However, I would like to drop most of the other tables (around 10) and repopulate them with data from the new database that I'm going to ship. In prior versions, I could just drop the database and copy over the new one. Going forward this won't be possible because I'm going to allow users to enter data in separate tables.

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Instead dropping the entire database and repopulating from scratch, consider using DROP TABLE explicitly. A healthy dose of ALTER TABLE .. RENAME may also be in order to put the "new" tables where the "old" tables were. And perhaps clean up with a VACUUM at the end to keep things tidy.

If the new data is distributed in a new database file, then consider using ATTACH DATABASE temporarily for the copy operation.

In my databases I have a meta-data table which stores the "database version" among other things (although the USER_VERSION PRAGMA could also be used). This enables code to selectively roll-forward through change-sets.

Happy coding.