list is showing incorrect entry using MVVM and sqlite

Question

im using sqlite with mvvm..but when i click add new and submit comming back to listing page it is not updated record in list.but when i kill app again come to list page it is showing record with duplicate entries of same record.i dont know where my code is getting wrong..plz help

db helper:-

public class DbHelper extends SQLiteOpenHelper {

private static final int DATABASE_VERSION = 2;

static final String DATABASE_NAME = "kuncorosqlite.db";

public static final String TABLE_SQLite = "sqlite";

public static final String COLUMN_ID = "id";
public static final String COLUMN_NAME = "name";
public static final String COLUMN_ADDRESS = "address";
ArrayList<HashMap<String, String>> listofMaps = new ArrayList();

public DbHelper(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {
    final String SQL_CREATE_MOVIE_TABLE = "CREATE TABLE " + TABLE_SQLite + " (" +
            COLUMN_ID + " INTEGER PRIMARY KEY autoincrement, " +
            COLUMN_NAME + " TEXT NOT NULL, " +
            COLUMN_ADDRESS + " TEXT NOT NULL" +
            " )";

    db.execSQL(SQL_CREATE_MOVIE_TABLE);
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("DROP TABLE IF EXISTS " + TABLE_SQLite);
    onCreate(db);
}

public MutableLiveData<ArrayList<HashMap<String, String>>> getAllData() {
    MutableLiveData<ArrayList<HashMap<String, String>>> wordList;
    wordList = new MutableLiveData<ArrayList<HashMap<String, String>>>();
    String selectQuery = "SELECT * FROM " + TABLE_SQLite;
    SQLiteDatabase database = this.getWritableDatabase();
    Cursor cursor = database.rawQuery(selectQuery, null);
    if (cursor.moveToFirst()) {
        do {
            HashMap<String, String> map = new HashMap<String, String>();
            map.put(COLUMN_ID, cursor.getString(0));
            map.put(COLUMN_NAME, cursor.getString(1));
            map.put(COLUMN_ADDRESS, cursor.getString(2));
            

            listofMaps.add(map);

            wordList.postValue(listofMaps);
        } while (cursor.moveToNext());
    }

    Log.e("select sqlite ", "" + wordList);

    database.close();
    return wordList;
}

public void insert(String name, String address) {
    SQLiteDatabase database = this.getWritableDatabase();
    String queryValues = "INSERT INTO " + TABLE_SQLite + " (name, address) " +
            "VALUES ('" + name + "', '" + address + "')";

    Log.e("insert sqlite ", "" + queryValues);
    database.execSQL(queryValues);
    database.close();
}

public void update(int id, String name, String address) {
    SQLiteDatabase database = this.getWritableDatabase();

    String updateQuery = "UPDATE " + TABLE_SQLite + " SET "
            + COLUMN_NAME + "='" + name + "', "
            + COLUMN_ADDRESS + "='" + address + "'"
            + " WHERE " + COLUMN_ID + "=" + "'" + id + "'";
    Log.e("update sqlite ", updateQuery);
    database.execSQL(updateQuery);
    database.close();
}

public void delete(int id) {
    SQLiteDatabase database = this.getWritableDatabase();

    String updateQuery = "DELETE FROM " + TABLE_SQLite + " WHERE " + COLUMN_ID + "=" + "'" + id + "'";
    Log.e("update sqlite ", updateQuery);
    database.execSQL(updateQuery);
    database.close();
}

}

viewmodel:-

public class Viewmodell extends AndroidViewModel {

private DbHelper repository ;
 MutableLiveData<ArrayList<HashMap<String, String>>> allNotesLivedata;
public Viewmodell(@NonNull Application application) {
    super(application);
    repository = new DbHelper(application);
    allNotesLivedata = repository.getAllData();
}
void insert(String name,String Address) {
    repository.insert(name,Address);
}
void update(int id, String name, String address) {
    repository.update(id,name,address);
}
void delete(int id) {
    repository.delete(id);
}
public LiveData<ArrayList<HashMap<String, String>>> getAllNotes() {
    return allNotesLivedata;
}

}

mainactivity (listing page):-

public class MainActivity extends AppCompatActivity {

ListView listView;
AlertDialog.Builder dialog;
List<Data> itemList = new ArrayList<Data>();
Adapter adapter;
DbHelper SQLite = new DbHelper(this);
Viewmodell viewmodell;
public static final String TAG_ID = "id";
public static final String TAG_NAME = "name";
public static final String TAG_ADDRESS = "address";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);

    SQLite = new DbHelper(getApplicationContext());
    viewmodell = ViewModelProviders.of(this).get(Viewmodell.class);

    FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
    listView = (ListView) findViewById(R.id.list_view);

    fab.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            Intent intent = new Intent(MainActivity.this, AddEdit.class);
            startActivity(intent);
        }
    });

    adapter = new Adapter(MainActivity.this, itemList);
    listView.setAdapter(adapter);
    listView.setOnItemClickListener(new android.widget.AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            final String idx = itemList.get(position).getId();
            final String name = itemList.get(position).getName();
            final String address = itemList.get(position).getAddress();
            Intent intent = new Intent(MainActivity.this, DetailsAct.class);
            intent.putExtra(TAG_ID, idx);
            intent.putExtra(TAG_NAME, name);
            intent.putExtra(TAG_ADDRESS, address);
            startActivity(intent);
        }
    });

    getAllData();

}

private void getAllData() {
    viewmodell.getAllNotes();
    viewmodell.allNotesLivedata.observe(this, new Observer<ArrayList<HashMap<String, String>>>() {
        @Override
        public void onChanged(ArrayList<HashMap<String, String>> hashMaps) {
            for (int i = 0; i < hashMaps.size(); i++) {
                String id = hashMaps.get(i).get(TAG_ID);
                String poster = hashMaps.get(i).get(TAG_NAME);
                String title = hashMaps.get(i).get(TAG_ADDRESS);

                Data data = new Data();

                data.setId(id);
                data.setName(poster);
                data.setAddress(title);

                itemList.add(data);
            }

            adapter.notifyDataSetChanged();
        }


    });
}

@Override
protected void onResume() {
    super.onResume();
    itemList.clear();
    getAllData();
}

You need to debug your code in order to know what is the fault happening . There is nothing wrong with the code — Karunesh Palekar, Aug 27 '21 at 09:26
@KaruneshPalekar if replace by `postvalue` by `setvalue` then duplication issue gone...but on resume the list not updating...only after killing application and then opening app then shows record in list — IRON MAN, Aug 27 '21 at 10:47
This has something to do with your LiveData . debug liveData and see whether it is returning data when your data is updated . — Karunesh Palekar, Aug 27 '21 at 10:50
@KaruneshPalekar i debug this line `return allNotesLivedata;` the new record is not returning — IRON MAN, Aug 27 '21 at 10:57
for example :-onresume it returning 6 record...after oncreate this livedata line returns 7 records — IRON MAN, Aug 27 '21 at 11:00

Dương Minh · Accepted Answer · 2021-08-27T15:13:51.033

1

Here I see you are having problems with LiveData.

Your LiveData seems to be having problems calling viewModel.getAllNotes() on the onResume() of your activity.

With you calling viewModel.getAllNote(), it actually returns LiveData, you don't set the value for that LiveData. That's why when you call viewModel.getAllNote() the LiveData allNotesLivedata is not triggered.

LiveData allNotesLivedata only actually triggers in Constructor of ViewModel via repository.getAllData(). repository.getAllData() is actually where you set the value for LiveData.

Replace the function getAllNotes() in the ViewModel in the following way:

public LiveData<ArrayList<HashMap<String, String>>> getAllNotes() {
    return repository.getAllData();
}

Edit 1:

I am seeing you have duplicate entity. it's onResume() that is called multiple times in the Activity's lifecycle.

And when you call onResume(), you call the function getAllData() in DbHelper. You are setting the value for LiveData to listofMap.

I see you are not resetting the old list, and you are adding each new item received from SQLite to the old list. That results in listofMap consisting of old item + new item of SQLite (includes all previous record + new record). So please reset listofMap before adding new item from SQLite.

public class DbHelper extends SQLiteOpenHelper {
    public MutableLiveData<ArrayList<HashMap<String, String>>> getAllData() {
        ...
        if (cursor.moveToFirst()) {
            listofMap = new ArrayList();
            // Continue your code
            do {
                ...
            }
        }
    }
}

edited Aug 27 '21 at 15:13

answered Aug 27 '21 at 14:47

Dương Minh

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duplicates entries are getting on oncreate(first time) – IRON MAN Aug 27 '21 at 14:58
after adding new records when comming back to list activity the new recored is seen n also again duplicates enteries enter...now total 4 times duplicate plus one new record is seen onResume – IRON MAN Aug 27 '21 at 15:03
what might be the issue? @Duong – IRON MAN Aug 27 '21 at 15:04
Because you call it at `onResume()`. And in `getAllData()` function of `DbHelper`, you are saying that every time you call `getAllData()` you are adding new values to `listofMaps`. You should clear `listofMaps` before adding it. – Dương Minh Aug 27 '21 at 15:04
@IRONMAN I have updated the comment already. – Dương Minh Aug 27 '21 at 15:14
@IRONMAN Happy to help! – Dương Minh Aug 27 '21 at 15:16
hi can u help me out here -> https://stackoverflow.com/questions/76480901/facing-issue-while-making-dynamic-views-using-relative-layout – IRON MAN Jun 15 '23 at 11:19

list is showing incorrect entry using MVVM and sqlite

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