android - Upgrading database using my OpenHelper in greendao -

i use greendao orm. want migrate schema oldversion new version. use this link implement mygration. wrote own openhelper class , put package. implement onupgrade method this:

public class upgradehelper extends openhelper {  public upgradehelper(context context, string name, cursorfactory factory) {     super(context, name, factory); }  /**  * apply appropriate migrations update database.  */ @override public void onupgrade(sqlitedatabase db, int oldversion, int newversion) {     log.i("greendao", "my upgrade helper -------- upgrading schema version " + oldversion + " " + newversion + " dropping tables");     switch (newversion) {     case 2:         new migratev1tov2().applymigration(db, oldversion);         break;     case 3:         new migratev2tov3().applymigration(db, oldversion);         break;     default:         return;     } } 

}

but method never called when upgrade version of database 1 2. can not change onupgrade() method in generated daomaster class, because auto generated. when upgrade schema_version, onupgrade() method called in daomaster class , can not modify it.

the onupgrade(database, oldschemaversion, newschemaversion)-method called if schema-version stored in sqlite-database differs schema-version specify in code.

thus method run once each version of database. if forgot include update-logic in first run, have reset schema-version manually example using sqlitemanager.