Using in-memory sqlite android

Question

I've been reading, browsing, searching a lot on this, I've criss-crossed stackoverflow back and forth many times and I managed to narrow my problem as much as I could.

The only thing I do not understand, is how to fully use an in-memory SQLite database.

Here is my situation - I have an encrypted SQLite database which I decrypt during the loading of my application (this part works for sure). My class that interacts with the database works for sure with a plain database. So to make it short, everything is flawless with a plain DB which gets loaded from the internal phone memory, but I am not sure how or where to store the decrypted DB in memory so it would get interpreted as normal DB.

I guess I should put null instead of a name in super(context, null, null, 3); and use :memory: instead of a path in SQLiteDatabase.openDatabase(), but I still don't understand fully. It says it cannot find an android_metadata table, but I am certain the database is as it should be.

Hope I was clear on this :)

Answer 1

SQLiteOpenHelper() will create an in-memory database if the name is null. Note that it will be created when you invoke getWritableDatabase().

Then you should insert your data.

Answer 2

You (or the framework) create a database using ONE of the following:

• SQLiteDatabase.create()
• SQLiteDatabase.openDatabase()
• SQLiteDatabase.openOrCreateDatabase()

The first option is the only way to create a memory-only database, the other two open or create a database file.

Consequently, if you are using SQLiteOpenHelper() and you pass name as null, the framework calls SQLiteDatabase.create(null), so you will get a database that only lives in memory (it dies when close() is called). There is no need to also call one of the other direct methods. Instead call getReadableDatabase() or getWritableDatabase() from your helper.