SelectSQL error on SQLite

I make SQLite test program.

I make sensordata database as:
sqlite> select * from sensor;

This is error. why?

This is open event handler.

This is db property.

any help?

What you’ve done in the second screenshot is created a local variable named the same as your app property. Instead, you’re going to want to create a new instance of SQLiteDatabase in the app property like this:

self.db = new SQLiteDatabase self.db.DatabaseFile = ...

I fix it. and bug is fixed. Thank you!