Rollback

@Insert(onConflict = OnConflictStrategy.ROLLBACK)

@Update(onConflict = OnConflictStrategy.ROLLBACK)

What SQLite Does

This strategy maps to INSERT OR ROLLBACK or UPDATE OR ROLLBACK statements.

It rolls back the transaction, as you might expect given the name.

Effects in Room

Frankly, it does not work very well. The Room-generated code does not expect the transaction to be rolled back, and so its call to endTransaction() fails with an obscure SQLiteException.

Since ABORT and FAIL also have the net effect in Room of rolling back the transaction, they are better choices.