green dao update column on play store update has taken place

Question

this is my Generator class

public class Generator {
    public static void main(String[] args) throws Exception {
        Schema schema = new Schema(1, "app.abc.db.dao");
        createAbcDB(schema);

    }
    private static void createAbcDB(Schema schema) throws IOException, Exception {
        Entity abc = schema.addEntity("Abc");
        abc.addIdProperty();
        abc.addShortProperty("name");
    }
}

This is the code where i get abc dao from dao session. This works fine.

DaoMaster.DevOpenHelper devOpenHelper = new DaoMaster.DevOpenHelper(SurveyActivity.this, "abc.db", null);
        SQLiteDatabase db = devOpenHelper.getWritableDatabase();
        DaoMaster daoMaster = new DaoMaster(db);
        DaoSession daoSession = daoMaster.newSession(IdentityScopeType.None);
        abcDao = daoSession.getAbcDao();

I added one more column

abc.addShortProperty("email");

to createAbcDB in generator to new version of app. Once users get updated they are getting sql exception saying no column found. Because i am calling on new login

dropAllTables(db, true);
onCreate(db); 

But problem is i have given one time login that user will always come to landing screen on upgrade from play store. So i don't know whether the user is upgraded app or not in order to drop and create all tables.

So my question is how to know my table has altered?

Answer 1

Each time that you do a significant modification like this, you have to update de Schema version number:

Schema schema = new Schema(2, "app.abc.db.dao");

This way, in the OpenHelper present in the DaoMaster, or in the SQLiteOpenHelper taht you're using, you can control this changes in onUpgrade() function:

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    Log.i("greenDAO", "Upgrading schema from version " + oldVersion + " to " + newVersion + " by dropping all tables");
    dropAllTables(db, true);
    onCreate(db);
}