Database structure

Database structure of application will be as much simple as possible:
There will be two tables: lists and items :

Usualy, in android, SqlLite database is used. Here is the code i wrote for creating the database :

 //create lists table
 private static final String LISTS_TABLE_CREATE =
 "create table lists ("
 +"_id integer primary key autoincrement, "
 +" listName text not null"
 +" );";
 
 //create items table
 private static final String ITEMS_TABLE_CREATE =
 "create table list_items ("
 +"_id integer primary key autoincrement, "
 +" isdone boolean  not null DEFAULT false,"
 +" title text not null,"
 +" list_id integer,"
 +" quantity integer not null DEFAULT 1,"
 +" FOREIGN KEY(list_id) REFERENCES lists(_id)" 
 +" );";  

 
 private final Context context;
 private DatabaseHelper DBHelper;
 private SQLiteDatabase db;
 public DBAdapter(Context ctx)
 {
    this.context = ctx;
    DBHelper = new DatabaseHelper(context);
 } 
 
 
 
 
 private static class DatabaseHelper extends SQLiteOpenHelper
 {
  DatabaseHelper(Context context)
  {
     super(context, DATABASE_NAME, null, DATABASE_VERSION);
  }
  @Override
  public void onCreate(SQLiteDatabase db)
  {
   
     try {
      
      db.execSQL(LISTS_TABLE_CREATE );
      db.execSQL(ITEMS_TABLE_CREATE );
      
   } 
      catch (Exception e){
       e.printStackTrace();
   }
  }
  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion)  
  {/*
   Log.w(TAG, "Upgrading database from version " + oldVersion
   + " to "
   + newVersion + ", which will destroy all old data");*/
   db.execSQL("DROP TABLE IF EXISTS " + ITEMS_TABLE_NAME);
   db.execSQL("DROP TABLE IF EXISTS " + LISTS_TABLE_NAME);
   onCreate(db);
  }
 }