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Retrieve Data As String From SQLite Database in Android Studio

I want to save name in the SQLite Database and later in another activity I want to retrieve that name as a String Value. But I am not being able to get data from the database. Help me please. My code is given below,
Database Helper:
private static final String TAG = "DatabaseHelper";
private static final String TABLE_NAME = "user";
private static final String COL1 = "ID";
private static final String COL2 = "name";
public void onCreate(SQLiteDatabase db) {String createTable =
"CREATE TABLE " + TABLE_NAME + " (ID INTEGER PRIMARY KEY
AUTOINCREMENT, " + COL2 +" TEXT)";
db.execSQL(createTable);}
public boolean addData(String item) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL2, item);
Log.d(TAG, "addData: Adding " + item + " to " + TABLE_NAME);
long result = db.insert(TABLE_NAME, null, contentValues);
if (result == -1) {
return false;
} else {
return true;
}
}
MainActivity:
mDatabaseHelper=new DatabaseHelper(this);
Username=(EditText)findViewById(R.id.user);
saveBtn=(Button)findViewById(R.id.button);
saveBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String newEntry = Username.getText().toString();
AddData(newEntry);
Username.setText("");
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
}
});
}
public void AddData(String newEntry) {
boolean insertData = mDatabaseHelper.addData(newEntry);
}
}
HomeActivity:
public class HomeActivity extends AppCompatActivity {
DatabaseHelper mDatabaseHelper;
String Username;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mDatabaseHelper = new DatabaseHelper(this);
}
}
Here, in this home activity i want to get the username as a string but I don't know how to do that. Help me please...

To retrieve data, you run a query that extracts the data into a Cursor. The Cursor will consist of 0-n rows and will have as many columns as defined in the query. You then move through the rows and use the appropriate Cursor get????? methods to get the actual data.
As an example you could add the following method to your DatabaseHelper :-
public String getName(long id) {
String rv = "not found";
SqliteDatabase db = this.getWritableDatabase();
String whereclause = "ID=?";
String[] whereargs = new String[]{String.valueOf(id)};
Cursor csr = db.query(TABLE_NAME,null,whereclause,whereargs,null,null,null);
if (csr.moveToFirst()) {
rv = csr.getString(csr.getColumnIndex(COL2));
}
return rv;
}
The above can then be used by String name = mDatabaseHelper.getName(1);.
Note that this assumes that a row with an ID of 1 exists.

Your Database Helper:
private static final String TAG = "DatabaseHelper";
private static final String TABLE_NAME = "user";
private static final String COL1 = "ID";
private static final String COL2 = "name";
private static final String createTable = "CREATE TABLE " + TABLE_NAME + " (" + COL1 +" INTEGER PRIMARY KEY AUTOINCREMENT, " + COL2 +" TEXT)"; // You have written ID inplace of COL1
public DatabaseHelper(Context context)
{
super(context,DB_NAME,null,1);
}
public void onCreate(SQLiteDatabase db)
{
db.execSQL(createTable);
}
public boolean insertData(String name) {
SQLiteDatabase sqLiteDatabase = this.getWritableDatabase();
ContentValues contentValues1 = new ContentValues();
contentValues1.put(COL2,name);
long result1 = sqLiteDatabase.insert(TABLE_NAME,null,contentValues1);
return result1 != -1;
}
public Cursor viewData()
{
SQLiteDatabase sqLiteDatabase = this.getReadableDatabase();
Cursor cursor ;
String query = "Select * from " +TABLE_NAME;
cursor= sqLiteDatabase.rawQuery(query, null);
return cursor;
}
Your Main Activity:
mDatabaseHelper=new DatabaseHelper(this);
Username=(EditText)findViewById(R.id.user);
saveBtn=(Button)findViewById(R.id.button);
saveBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String newEntry = Username.getText().toString();
mDatabaseHelper.insertData(newEntry);
Username.setText("");
Intent intent = new Intent(MainActivity.this, HomeActivity.class);
startActivity(intent);
}
});
}
}
Your Home Activity:
public class HomeActivity extends AppCompatActivity {
DatabaseHelper mDatabaseHelper;
String Username;
ArrayList<String> listItem;
ArrayAdapter adapter;
ListView listView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
mDatabaseHelper = new DatabaseHelper(this);
listView = (ListView) findViewById(R.id.listView);
listItem = new ArrayList<>();
viewData1();
}
private void viewData1() {
Cursor cursor = mDatabaseHelper.viewData();
if (cursor.getCount() == 0) {
Toast.makeText(this, "No data to show", Toast.LENGTH_SHORT).show();
} else {
while (cursor.moveToNext()) {
Log.i("message","Data got");
listItem.add(cursor.getString(1)); // Adding data received to a Listview
}
adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, listItem);
listView.setAdapter(adapter);
}
}
}

check it out this library
it is very easy to implement
https://github.com/wisdomrider/SqliteClosedHelper

Delete data from ListView (Android Studio)

I have 3 java classes (MainActivity, DatabaseOpenHelper and DatabaseAccess)
My add and show buttons work perfectly, but not my delete button. Add adds name and nickname into the database, show shows the list of names in the same layout under the buttons.
Here is my code in MainActivity.class
public class MainActivity extends AppCompatActivity {
public EditText name123, dogName, dogNickname;
public Button query_button, add_button, show_button, delete_button;
public TextView result_address;
public ListView listView;
ArrayList<String> naziv = new ArrayList<>();
ArrayAdapter<String> adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
name123 = findViewById(R.id.name);
query_button = findViewById(R.id.query_button);
result_address = findViewById(R.id.result);
dogName = findViewById(R.id.et_dogName);
dogNickname = findViewById(R.id.et_dogNickname);
add_button = findViewById(R.id.add_button);
show_button = findViewById(R.id.show_button);
delete_button = findViewById(R.id.delete_button);
listView = findViewById(R.id.doglistview);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_selectable_list_item, naziv);
add_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getApplicationContext());
databaseAccess.open();
long result = databaseAccess.add(dogName.getText().toString(), dogNickname.getText().toString());
if(result > 0){
dogName.setText("");
dogNickname.setText("");
} else {
Toast.makeText(getApplicationContext(), "Dodaj ime i nadimak", Toast.LENGTH_SHORT).show();
}
databaseAccess.close();
}
});
show_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
naziv.clear();
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getApplicationContext());
databaseAccess.open();
Cursor cnn = databaseAccess.getAllNames();
while (cnn.moveToNext()){
String name = cnn.getString(0);
naziv.add(name);
}
listView.setAdapter(adapter);
databaseAccess.close();
}
});
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Toast.makeText(getApplicationContext(), naziv.get(position), Toast.LENGTH_SHORT).show();
}
});
//setting onclicklistener to query button
query_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//create the instance of database access class and open database connection
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getApplicationContext());
databaseAccess.open();
//getting sting value of edittext
String n = name123.getText().toString();
String address = databaseAccess.getAddress(n);//getAddress method to get address
//setting text to result field
result_address.setText(address);
databaseAccess.close();
}
});
delete_button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DatabaseAccess databaseAccess = DatabaseAccess.getInstance(getApplicationContext());
databaseAccess.open();
Integer deletedRows = databaseAccess.deleteData("id_dogName");
if (deletedRows > 0){
Toast.makeText(MainActivity.this, "Deleted data", Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(MainActivity.this, "Data not deleted", Toast.LENGTH_SHORT).show();
}
databaseAccess.close();
}
});
}
}
And here is the code from DatabaseAccess.class:
public class DatabaseAccess {
static final String NAME = "name_dogName";
static final String NICKNAME = "nickname_dogName";
static final String TBNAME = "dogName";
static final String ROWID = "id_dogName";
private SQLiteOpenHelper openHelper;
private SQLiteDatabase db;
private static DatabaseAccess instance;
Cursor c = null;
//private constructor so that object creation from outside the class is avoided
private DatabaseAccess(Context context)
{
openHelper = new DatabaseOpenHelper(context);
}
//to return the single instance of database
public static DatabaseAccess getInstance(Context context)
{
if(instance == null)
{
instance = new DatabaseAccess(context);
}
return instance;
}
//to open the database
public void open()
{
db = openHelper.getWritableDatabase();
}
//closing the database connection
public void close()
{
if(db!=null)
{
db.close();
}
}
//method to query and return the results from database
//query for address by passing name
public String getAddress(String name)
{
c = db.rawQuery("select nickname_dogName from dogName where name_dogName = ?", new String[]{name});
String nickname = "";
while (c.moveToNext())
{
String address = c.getString(0);
nickname += address;
}
return nickname;
}
//add
public long add(String name, String nickname){
try {
ContentValues contentValues = new ContentValues();
contentValues.put(NAME, name);
contentValues.put(NICKNAME, nickname);
return db.insert(TBNAME, ROWID, contentValues);
} catch (SQLException e){
e.printStackTrace();
}
return 0;
}
public Cursor getAllNames (){
String[] columns = {NAME, ROWID, NICKNAME};
return db.query(TBNAME, columns, null, null, null, null, null);
}
public Integer deleteData (String id){
return db.delete(TBNAME, "id_dogName", new String[]{id});
}
}
When I click on my phone on the delete button it throws me out of the app. How to correct my code and make the delete button delete a selected item from the list?

something wrong in the second argument, your where clause should include "=?"
public Integer deleteData (String id){
return db.delete(TBNAME, "id_dogName=?", new String[]{id});
}

SQLite - RecyclerView - many tables do not work

I have a problem with creating two tables in sqlite and display them in RecyclerView and more specifically with one table. I add to the question a screenshot of the application so that you can understand what the problem is.
I have 3 activities: FirstActivity, in which there are two buttons (Monday and Tuesday) -> from this activity we go to MainActivity, on the button selection (Monday) -> save data in table_MON and after selection button (Tuesday) in the table_Tue. The problem is that everything works correctly, when we press the button (Monday) we can save the training, edit and delete it. However, when we go to the button (Tuesday) we can only add training, but we can't edit or delete them. However, I have no idea why? I am already looking at this problem for a week and I have no idea what is going on, maybe a fresh look will help solve the problem.
My database consists of two tables: tableMon and tableTue, but I use the same columns in it (exercises, weight etc ..), and separate _id, and I do not know if this can be a problem. Perhaps the problem is that I use MainActivity in both cases?
Screenshot App:
FirstActivity
enter image description here
Click button Monday --> MainActivity.class
enter image description here
Click button Tuesday --> MainActivity.class
enter image description here
Button Tuesday --> DetailActivity and her is the problem I can't update and delete training.
enter image description here
FirstActivity.class
public class FirstActivity extends AppCompatActivity {
Button buttonMon, buttonTue;
public static final String BUTTON_KEY1 = "BUTTON_KEY";
public static final String BUTTON_KEY2 = "BUTTON_KEY2";
public static final String BUTTON_VALUE = "1";
public static final String BUTTON_VALUE2 = "2";
public static boolean WAS_RUNNING;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_first);
buttonMon = (Button) findViewById(R.id.buttonMonday);
buttonTue = (Button) findViewById(R.id.buttonTuesday);
WAS_RUNNING = false;
//OPEN THE SAME MAINACTIVITY
buttonMon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
WAS_RUNNING = true;
Intent intent = new Intent(FirstActivity.this, MainActivity.class);
intent.putExtra(BUTTON_KEY1, BUTTON_VALUE);
startActivity(intent);
} });
//OPEN THE SAME MAINACTIVITY
buttonTue.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
WAS_RUNNING = true;
Intent i = new Intent(FirstActivity.this, MainActivity.class);
i.putExtra(BUTTON_KEY2, BUTTON_VALUE2);
startActivity(i);
} });}}
MainActivity.class
public class MainActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private MyAdapter myAdapter;
private ArrayList<Training> trainingArrayList = new ArrayList<Training>();
private EditText editTextExercise, editTextWeight, editTextRepeat, editTextSeries;
private Button buttonSave, buttonBack;
private Dialog dialog;
private String value;
private String value2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Bundle bundle = getIntent().getExtras();
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
showDialog();}});
if(bundle == null)
{return;}
value = bundle.getString(FirstActivity.BUTTON_KEY1);
value2 = bundle.getString(FirstActivity.BUTTON_KEY2);
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
if(value != null) {
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setItemAnimator(new DefaultItemAnimator());
myAdapter = new MyAdapter(this, trainingArrayList);
//Refresh MON TABLE
refreshMonTable();
}else if(value2 != null) {
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setItemAnimator(new DefaultItemAnimator());
myAdapter = new MyAdapter(this, trainingArrayList);
//Refresh TUE TABLE
refreshTueTable(); }}
public void showDialog()
{
dialog = new Dialog(this);
dialog.setContentView(R.layout.dialog_layout);
editTextExercise = (EditText) dialog.findViewById(editTextExerciseDialog);
editTextWeight = (EditText) dialog.findViewById(editTextWeightDialog);
editTextRepeat = (EditText) dialog.findViewById(editTextRepeatDialog);
editTextSeries = (EditText) dialog.findViewById(editTextSeriesDialog);
buttonSave = (Button) dialog.findViewById(buttonSaveDialog);
buttonBack = (Button) dialog.findViewById(buttonBackDialog);
buttonBack.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
dialog.dismiss();}});
buttonSave.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(value != null) {
saveDataMon(editTextExercise.getText().toString(),
String.valueOf(editTextWeight.getText().toString()),
String.valueOf(editTextRepeat.getText().toString()),
String.valueOf(editTextSeries.getText().toString()));
} else if(value2 != null) {
saveDataTue(editTextExercise.getText().toString(),
String.valueOf(editTextWeight.getText().toString()),
String.valueOf(editTextRepeat.getText().toString()),
String.valueOf(editTextSeries.getText().toString()));
}}});
dialog.show();}
private void saveDataMon(String exercise, String weight, String repeat, String series)
{
DBAdapter adapter = new DBAdapter(this);
adapter.openDatabase();
long result = adapter.addMon(exercise, weight, repeat, series);
if (result > 0) {
editTextExercise.setText("");
editTextWeight.setText("");
editTextRepeat.setText("");
editTextSeries.setText("");
dialog.dismiss();
} else {
Snackbar.make(editTextExercise, "Unable to save!", Snackbar.LENGTH_SHORT).show();}
adapter.closeDB();
refreshMonTable();}
private void saveDataTue(String exercise, String weight, String repeat, String series)
{
DBAdapter adapter = new DBAdapter(this);
adapter.openDatabase();
long result = adapter.addTue(exercise, weight, repeat, series);
if (result > 0) {
editTextExercise.setText("");
editTextWeight.setText("");
editTextRepeat.setText("");
editTextSeries.setText("");
dialog.dismiss();
} else {
Snackbar.make(editTextExercise, "Unable to save!", Snackbar.LENGTH_SHORT).show();
}
adapter.closeDB();
refreshTueTable();}
private void refreshMonTable()
{
DBAdapter adapter = new DBAdapter(this);
adapter.openDatabase();
trainingArrayList.clear();
Cursor cursor = adapter.getAllTreningMon();
if(cursor != null)
{ if(cursor.moveToFirst())
{
do {
int id = cursor.getInt(0);
String cwiczenie = cursor.getString(1);
String ciezar = cursor.getString(2);
String powtorzenia = cursor.getString(3);
String serie = cursor.getString(4);
Training training = new Training(id, cwiczenie, ciezar, powtorzenia, serie);
trainingArrayList.add(training);
}while (cursor.moveToNext());}}
recyclerView.setAdapter(myAdapter);
adapter.closeDB(); }
private void refreshTueTable()
{
DBAdapter adapter = new DBAdapter(this);
adapter.openDatabase();
trainingArrayList.clear();
Cursor cursor = adapter.getAllTreningTue();
if(cursor != null)
{ if(cursor.moveToFirst())
{
do {
int id = cursor.getInt(0);
String exercise = cursor.getString(1);
String weight = cursor.getString(2);
String repeat = cursor.getString(3);
String series = cursor.getString(4);
Training training = new Training(id, exercise, weight, repeat, series);
trainingArrayList.add(training);
}while (cursor.moveToNext());}}
recyclerView.setAdapter(myAdapter);
adapter.closeDB();
}
#Override
protected void onResume() {
super.onResume();
if(value != null) {
//REFRESH
refreshMonTable();
} else if(value2 != null) {
refreshTueTable();}}
#Override
public void onBackPressed() {
new AlertDialog.Builder(this)
.setTitle("Exit?")
.setMessage("Do you want to exit?")
.setNegativeButton("No", null)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
MainActivity.super.onBackPressed();
}
}).create().show();}}
DetailActivity.class
public class DetailActivity extends AppCompatActivity {
private EditText editTextExerciseDetail, editTextWeightDetail, editTextRepeatDetail, editTextSeriesDetail;
private Button buttonUpdate;
private Button buttonDelete;
String mon;
String tue;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
Bundle intent = getIntent().getExtras();
if(intent == null)
{return;}
mon = intent.getString(MyAdapter.KEY_MON);
tue = intent.getString(MyAdapter.KEY_TUE);
final int idT = intent.getInt("id");
String cwiczenie = intent.getString("exercise");
String ciezar = intent.getString("weight");
String powtorzenia = intent.getString("repeat");
String serie = intent.getString("series");
editTextExerciseDetail = (EditText) findViewById(R.id.exerciseEditTxtDetail);
editTextWeightDetail = (EditText) findViewById(R.id.weightEditTextDetail);
editTextRepeatDetail = (EditText) findViewById(R.id.repeatEditTextDetail);
editTextSeriesDetail = (EditText) findViewById(R.id.seriesEditTextDetail);
buttonUpdate = (Button) findViewById(R.id.updateBtn);
buttonDelete = (Button) findViewById(R.id.deleteBtn);
editTextExerciseDetail.setText(cwiczenie);
editTextWeightDetail.setText(ciezar);
editTextRepeatDetail.setText(powtorzenia);
editTextSeriesDetail.setText(serie);
buttonUpdate.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if(mon != null) {
updateMon(idT, editTextExerciseDetail.getText().toString(),
editTextWeightDetail.getText().toString(),
editTextRepeatDetail.getText().toString(),
editTextSeriesDetail.getText().toString());
} else if(tue != null) {
updateTue(idT, editTextExerciseDetail.getText().toString(),
editTextWeightDetail.getText().toString(),
editTextRepeatDetail.getText().toString(),
editTextSeriesDetail.getText().toString());}}
});
buttonDelete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder builder = new AlertDialog.Builder(DetailActivity.this);
builder.setMessage("Do you want delete this training?")
.setTitle("Delete")
.create();
builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
if(mon != null) {
deleteMon(idT);
}else if(tue != null){
deleteTue(idT);}}});
builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}});
builder.show();}});}
//Update MON TABLE
private void updateMon(int id, String newExercise, String newWeight, String newRepeat, String newSeries)
{
DBAdapter dbAdapter = new DBAdapter(this);
dbAdapter.openDatabase();
long result = dbAdapter.updateMon(id, newExercise, newWeight, newRepeat, newSeries);
if(result > 0)
{
editTextExerciseDetail.setText(newExercise);
editTextWeightDetail.setText(newWeight);
editTextRepeatDetail.setText(newRepeat);
editTextSeriesDetail.setText(newSeries);
this.finish();
Snackbar.make(editTextExerciseDetail, "Updated Succesfully", Snackbar.LENGTH_SHORT).show();
}else
{
Snackbar.make(editTextExerciseDetail, "Unable to updated", Snackbar.LENGTH_SHORT).show();
}
dbAdapter.closeDB();
}
//Update TUE TABLE
private void updateTue(int id, String newExercise, String newWeight, String newRepeat, String newSeries)
{
DBAdapter dbAdapter = new DBAdapter(this);
dbAdapter.openDatabase();
long result = dbAdapter.updateTue(id, newExercise, newWeight, newRepeat, newSeries);
if(result > 0)
{
editTextExerciseDetail.setText(newExercise);
editTextWeightDetail.setText(newWeight);
editTextRepeatDetail.setText(newRepeat);
editTextSeriesDetail.setText(newSeries);
this.finish();
Snackbar.make(editTextExerciseDetail, "Updated Succesfully", Snackbar.LENGTH_SHORT).show();
}else
{
Snackbar.make(editTextExerciseDetail, "Unable to updated", Snackbar.LENGTH_SHORT).show();
}
dbAdapter.closeDB();}
//DELETE MON TABLE
private void deleteMon(int id)
{
DBAdapter dbAdapter = new DBAdapter(this);
dbAdapter.openDatabase();
long result = dbAdapter.deleteMon(id);
if(result>0)
{
this.finish();
}else
{
Snackbar.make(editTextExerciseDetail, "Unable to deleted", Snackbar.LENGTH_SHORT).show();
}
dbAdapter.closeDB();
}
//DELETE TUE TABLE
private void deleteTue(int id)
{
DBAdapter dbAdapter = new DBAdapter(this);
dbAdapter.openDatabase();
long result = dbAdapter.deleteTue(id);
if(result>0)
{
this.finish();
}else
{
Snackbar.make(editTextExerciseDetail, "Unable to deleted", Snackbar.LENGTH_SHORT).show();
}
dbAdapter.closeDB();}
#Override
protected void onResume() {
super.onResume();}
#Override
protected void onRestart() {
super.onRestart();}}
DBHelper.class
public class DBHelper extends SQLiteOpenHelper {
//DB
static final String DB_NAME = "training_db";
static final int DB_VERSION = '1';
//TABLES
static final String TB_NAME_MON = "training_tb_mon";
static final String TB_NAME_TUE = "training_tb_tue";
//COLUMNS
static final String ROW_ID_MON = "id_Mon";
static final String ROW_ID_TUE = "id_Tue";
//ROW
static final String EXERCISE = "exercise";
static final String WEIGHT = "weight";
static final String REPEAT = "repeat";
static final String SERIES = "series";
static final String CREATE_TB_MON = "CREATE TABLE training_tb_mon (id_Mon INTEGER PRIMARY KEY AUTOINCREMENT,"
+ "exercise TEXT NOT NULL, weight TEXT NOT NULL, repeat TEXT NOT NULL, series TEXT NOT NULL);";
static final String CREATE_TB_TUE = "CREATE TABLE training_tb_tue (id_Tue INTEGER PRIMARY KEY AUTOINCREMENT,"
+ "exercise TEXT NOT NULL, weight TEXT NOT NULL, repeat TEXT NOT NULL, series TEXT NOT NULL);";
public DBHelper(Context context) {
super(context, DB_NAME, null, DB_VERSION);}
#Override
public void onCreate(SQLiteDatabase db) {
try {
db.execSQL(CREATE_TB_MON);
db.execSQL(CREATE_TB_TUE);
}catch (Exception e) {
e.printStackTrace();
}}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TB_NAME_MON);
db.execSQL("DROP TABLE IF EXISTS " + TB_NAME_TUE);
onCreate(db);
}}
DBAdapter.class
public class DBAdapter {
Context c;
DBHelper dbHelper;
SQLiteDatabase db;
public DBAdapter(Context c) {
this.c = c;
dbHelper = new DBHelper(c);
}
//OPEN DATABASE
public DBAdapter openDatabase() {
try {
db = dbHelper.getWritableDatabase();
}catch (SQLiteException e) {
e.printStackTrace();
}
return this;
}
//CLOSE DATABASE
public void closeDB()
{
try{
dbHelper.close();
}catch (SQLiteException e){
e.printStackTrace();
}}
//Add training Mon
public long addMon(String exercise, String weight, String repeat, String series)
{
try{
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.EXERCISE, exercise);
contentValues.put(DBHelper.WEIGHT, weight);
contentValues.put(DBHelper.REPEAT, repeat);
contentValues.put(DBHelper.SERIES, series);
return db.insert(DBHelper.TB_NAME_MON, DBHelper.ROW_ID_MON, contentValues);
}catch (SQLiteException e) {
e.printStackTrace(); }
return 0;}
//Add training Tue
public long addTue(String exercise, String weight, String repeat, String series)
{
try{
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.EXERCISE, exercise);
contentValues.put(DBHelper.WEIGHT, weight);
contentValues.put(DBHelper.REPEAT, repeat);
contentValues.put(DBHelper.SERIES, series);
return db.insert(DBHelper.TB_NAME_TUE, DBHelper.ROW_ID_TUE, contentValues);
}catch (SQLiteException e) {
e.printStackTrace();
}
return 0;
}
//REFRESH TABLE MON
public long updateMon(int id, String exercise, String weight, String repeat, String series)
{
try{
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.EXERCISE, exercise);
contentValues.put(DBHelper.WEIGHT, weight);
contentValues.put(DBHelper.REPEAT, repeat);
contentValues.put(DBHelper.SERIES, series);
contentValues.put(DBHelper.ROW_ID_MON, id);
return db.update(DBHelper.TB_NAME_MON, contentValues, DBHelper.ROW_ID_MON + " =?", new String[]{String.valueOf(id)});
}catch (SQLiteException e) {
e.printStackTrace(); }
return 0;
}
//REFRESH TABLE TUE
public long updateTue(int id, String exercise, String weight, String repeat, String series)
{
try{
ContentValues contentValues = new ContentValues();
contentValues.put(DBHelper.EXERCISE, exercise);
contentValues.put(DBHelper.WEIGHT, weight);
contentValues.put(DBHelper.REPEAT, repeat);
contentValues.put(DBHelper.SERIES, series);
contentValues.put(DBHelper.ROW_ID_TUE, id);
return db.update(DBHelper.TB_NAME_TUE, contentValues, DBHelper.ROW_ID_TUE + " =?", new String[]{String.valueOf(id)});
}catch (SQLiteException e) {
e.printStackTrace();
}
return 0;
}
//DELETE ROW TABLE MON
public long deleteMon(int id)
{
try{
return db.delete(DBHelper.TB_NAME_MON, DBHelper.ROW_ID_MON + " =?", new String[]{String.valueOf(id)});
}catch (SQLiteException e) {
e.printStackTrace();
}
return 0; }
//DELETE ROW TABLE TUE
public long deleteTue(int id)
{
try{
return db.delete(DBHelper.TB_NAME_TUE, DBHelper.ROW_ID_TUE + " =?", new String[]{String.valueOf(id)});
}catch (SQLiteException e) {
e.printStackTrace();}
return 0;}
//ALL TRAINING TABLE MON
public Cursor getAllTreningMon() {
try{
String[] columns = {DBHelper.ROW_ID_MON, DBHelper.EXERCISE, DBHelper.WEIGHT, DBHelper.REPEAT, DBHelper.SERIES};
return db.query(DBHelper.TB_NAME_MON, columns, null, null, null, null, null);
}catch (SQLiteException e)
{
e.printStackTrace();
}
return null;
}
//ALL TRAINING TABLE TUE
public Cursor getAllTreningTue() {
try{
String[] columns = {DBHelper.ROW_ID_TUE, DBHelper.EXERCISE, DBHelper.WEIGHT, DBHelper.REPEAT, DBHelper.SERIES};
return db.query(DBHelper.TB_NAME_TUE, columns, null, null, null, null, null);
}catch (SQLiteException e)
{
e.printStackTrace();
}
return null;}}
MyAdapter.class
public class MyAdapter extends RecyclerView.Adapter<MyHolder> {
Context c;
ArrayList<Training> training;
public static String KEY_MON = "KEY_MON";
public static String KEY_TUE = "KEY_TUE";
public static String VALUE_MON = "10";
public static String VALUE_TUE = "20";
public <T extends Training> MyAdapter(Context c, ArrayList<Training> training) {
this.c = c;
this.training = training;
}
#Override
public MyHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(c).inflate(R.layout.card_view_model, parent, false);
return new MyHolder(v);
}
#Override
public void onBindViewHolder(MyHolder holder, final int position) {
holder.textViewModel.setText(training.get(position).getExercise());
holder.setItemClickListener(new ItemClickListener() {
#Override
public void onItemClick(View v) {
if (FirstActivity.WAS_RUNNING)
{Intent intent = new Intent(c, DetailActivity.class);
intent.putExtra(KEY_MON, VALUE_MON);
intent.putExtra("id", training.get(position).getId());
intent.putExtra("exercise", training.get(position).getExercise());
intent.putExtra("weight", training.get(position).getWeight());
intent.putExtra("repeat", training.get(position).getRepeat());
intent.putExtra("series", training.get(position).getSeries());
c.startActivity(intent);
} else if (FirstActivity.WAS_RUNNING)
{Intent intent2 = new Intent(c, DetailActivity.class);
intent2.putExtra(KEY_TUE, VALUE_TUE);
intent2.putExtra("id", training.get(position).getId());
intent2.putExtra("exercise", training.get(position).getExercise());
intent2.putExtra("weight", training.get(position).getWeight());
intent2.putExtra("repeat", training.get(position).getRepeat());
intent2.putExtra("series", training.get(position).getSeries());
c.startActivity(intent2);
}}});}
#Override
public int getItemCount() {
return training.size();}}
Training.class
public class Training {
int id;
String exercise;
String weight;
String repeat;
String series;
public Training(int id, String exercise, String weight, String repeat, String series) {
this.id = id;
this.exercise = exercise;
this.weight = weight;
this.repeat = repeat;
this.series = series;
}
public int getId() {return id;}
public void setId(int id) { this.id = id;}
public String getExercise() {return exercise; }
public void setExercise(String exercise) {this.exercise = exercise;}
public String getWeight() {return weight;}
public void setWeight(String weight) {this.weight = weight; }
public String getRepeat() {return repeat;}
public void setRepeat(String repeat) { this.repeat = repeat;}
public String getSeries() {return series;}
public void setSeries(String series) {this.series = series;}}

In your MyAdapter class, in the onItemClick method, within the onBindViewHolder method, the second check, for Tue processing, would never run.
You have :-
if (FirstActivity.WAS_RUNNING) {
.......
} else if (FirstActivity.WAS_RUNNING) {
.......
}
i.e. you are saying if FirstActivity was not running and the FirstActivity was running then do your stuff.
i.e. the else will only be entered if FirstActivity were not running, in which case the if (FirstActivity.WAS_RUNNING) would never be true.
Perhaps have 2 booleans MONDAY_WAS_RUNNING and TUESDAY_WAS RUNNING (you could use just the existing boolean by setting that to false in the buttonTue listener doing the Tuesday processing in the else (without an if) ).
e.g. :-
FirstActivity class :-
public static boolean MONDAY_WAS_RUNNING;
public static boolean TUESDAY_WAS_RUNNING;
..........
buttonMon.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
MONDAY_WAS_RUNNING = true;
TUESDAY_WAS_RUNNING = false;
Intent intent = new Intent(FirstActivity.this, MainActivity.class);
intent.putExtra(BUTTON_KEY1, BUTTON_VALUE);
startActivity(intent);
} });
buttonTue.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TUESDAY_WAS_RUNNING = true;
MONDAY_WAS_RUNNING = false;
Intent i = new Intent(FirstActivity.this, MainActivity.class);
i.putExtra(BUTTON_KEY2, BUTTON_VALUE2);
startActivity(i);
} });}}
MyAdapter :-
#Override
public void onBindViewHolder(MyHolder holder, final int position) {
holder.textViewModel.setText(training.get(position).getExercise());
holder.setItemClickListener(new ItemClickListener() {
#Override
public void onItemClick(View v) {
if (FirstActivity.MONDAY_WAS_RUNNING)
{Intent intent = new Intent(c, DetailActivity.class);
intent.putExtra(KEY_MON, VALUE_MON);
intent.putExtra("id", training.get(position).getId());
intent.putExtra("exercise", training.get(position).getExercise());
intent.putExtra("weight", training.get(position).getWeight());
intent.putExtra("repeat", training.get(position).getRepeat());
intent.putExtra("series", training.get(position).getSeries());
c.startActivity(intent);
} else if (FirstActivity.TUESDAY_WAS_RUNNING)
{Intent intent2 = new Intent(c, DetailActivity.class);
intent2.putExtra(KEY_TUE, VALUE_TUE);
intent2.putExtra("id", training.get(position).getId());
intent2.putExtra("exercise", training.get(position).getExercise());
intent2.putExtra("weight", training.get(position).getWeight());
intent2.putExtra("repeat", training.get(position).getRepeat());
intent2.putExtra("series", training.get(position).getSeries());
c.startActivity(intent2);
}}});}
However I'd probably go for :-
#Override
public void onBindViewHolder(MyHolder holder, final int position) {
holder.textViewModel.setText(training.get(position).getExercise());
holder.setItemClickListener(new ItemClickListener() {
#Override
public void onItemClick(View v) {
Intent intent = new Intent(c, DetailActivity.class);
if (FirstActivity.MONDAY_WAS_RUNNING) {
intent.putExtra(KEY_MON, VALUE_MON);
} else {
intent.putExtra(KEY_TUE, VALUE_TUE);
}
intent.putExtra("id", training.get(position).getId());
intent.putExtra("exercise", training.get(position).getExercise());
intent.putExtra("weight", training.get(position).getWeight());
intent.putExtra("repeat", training.get(position).getRepeat());
intent.putExtra("series", training.get(position).getSeries());
c.startActivity(intent);
});
}
Note! the above code has not been checked, rather it is in-principle code

My application crashes after I try to insert an Item into my database [duplicate]

This question already has answers here:
What is a NullPointerException, and how do I fix it?
(12 answers)
Closed 5 years ago.
I can open my Datenbase but if I try to insert an item my application crashes.
Insert the item only to my ListView works.
I create a new Object in another Activity and take the Values in an Intent.
But when I start the intent and go back to the Main/List_page Activity my App crashes. Without the Database, the application runs.
Heres my codes: ReceptListAdapter.java:
public class ReceptListDatabase {
private static final String DATABASE_NAME = "receptlist.db";
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_TABLE = "receptlistitems";
public static final String KEY_ID = "_id";
public static final String KEY_NAME = "name";
public static final String KEY_KATEGORY = "kategory";
public static final String KEY_INGREDIENTS = "ingredients";
public static final String KEY_DIRECTIONS = "ingredients";
public static final int COLUMN_NAME_INDEX = 1;
public static final int COLUMN_KATEGORY_INDEX = 2;
public static final int COLUMN_INGREDIENTS_INDEX = 3;
public static final int COLUMN_DIRECTIONS_INDEX = 4;
private ReceptDBOpenHelper dbHelper;
private SQLiteDatabase DB;
public ReceptListDatabase(Context context) {
dbHelper = new ReceptDBOpenHelper(context, DATABASE_NAME, null,
DATABASE_VERSION);
}
public void open() throws SQLException {
try {
db = dbHelper.getWritableDatabase();
} catch (SQLException e) {
db = dbHelper.getReadableDatabase();
}
}
public void close() {
db.close();
}
public long insertReceptItem(ListItem item) {
ContentValues itemValues = new ContentValues();
itemValues.put(KEY_NAME, item.getName());
itemValues.put(KEY_KATEGORY,item.getKategory());
itemValues.put(KEY_INGREDIENTS, item.getIngredients());
itemValues.put(KEY_DIRECTIONS, item.getDirection());
return db.insert(DATABASE_TABLE, null, itemValues);
}
public void removeReceptItem(ListItem item) {
String toDelete = KEY_NAME + "=?";
String[] deleteArguments = new String[]{item.getName()};
db.delete(DATABASE_TABLE, toDelete, deleteArguments);
}
public ArrayList<ListItem> getAllReceptItems() {
ArrayList<ListItem> items = new ArrayList<ListItem>();
Cursor cursor = db.query(DATABASE_TABLE, new String[] { KEY_ID,
KEY_NAME, KEY_KATEGORY, KEY_INGREDIENTS, KEY_DIRECTIONS, null}, null, null, null, null, null);
if (cursor.moveToFirst()) {
do {
String name = cursor.getString(COLUMN_NAME_INDEX);
String kategory = cursor.getString(COLUMN_KATEGORY_INDEX);
String ingredients = cursor.getString(COLUMN_INGREDIENTS_INDEX);
String directions = cursor.getString(COLUMN_DIRECTIONS_INDEX);
items.add(new ListItem(name, kategory, ingredients, directions, null));
} while (cursor.moveToNext());
}
return items;
}
private class ReceptDBOpenHelper extends SQLiteOpenHelper {
private static final String DATABASE_CREATE = "create table "
+ DATABASE_TABLE + " (" + KEY_ID
+ " integer primary key autoincrement, " + KEY_NAME
+ " text not null, " + KEY_KATEGORY
+ " text, " + KEY_INGREDIENTS
+ " text not null, " + KEY_DIRECTIONS
+ " text not null);";
public ReceptDBOpenHelper(Context c, String dbname,
SQLiteDatabase.CursorFactory factory, int version) {
super(c, dbname, factory, version);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
}
}
And my Main Activity:
public class List_Page extends Activity {
private ListViewAdapter adapter;
private ArrayList<ListItem> itemList;
private ListView list;
private DatabaseAdapter receptDB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_list);
setupButton();
setupListView();
addObject();
setupDatabase();
}
private void setupDatabase() {
receptDB = new DatabaseAdapter(this);
receptDB.open();
}
private void setupButton() {
Button addItemButton = (Button) findViewById(R.id.addItemButton);
addItemButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
buttonClicked();
}
});
}
private void buttonClicked() {
//get EditText
Intent newItemIntent = new Intent(List_Page.this, Add_Object.class);
startActivity(newItemIntent);
finish();
}
private void setupListView() {
itemList = new ArrayList<ListItem>();
adapter = new ListViewAdapter(List_Page.this, itemList);
list = (ListView) findViewById(R.id.listItem);
list.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view,
int position, long id) {
//fehler bei removeTaskAtPosition(position);
return true;
}
});
View header = ((LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE)).inflate(R.layout.activity_list_item, null);
list.addHeaderView(header);
list.setAdapter(adapter);
}
private void addObject(){
Intent intent = getIntent();
if (intent.hasExtra(Constants.KEY_RECEPT_NAME)) {
String name = intent.getExtras().getString(Constants.KEY_RECEPT_NAME);
String kategory = intent.getExtras().getString(Constants.KEY_KATEGORY);
String ingredients = intent.getExtras().getString(Constants.KEY_INGREDIENTS);
String directions = intent.getExtras().getString(Constants.KEY_DIRECTIONS);
Bitmap image = (Bitmap) intent.getParcelableExtra(Constants.KEY_IMAGE);
ListItem newObject = new ListItem(name,kategory,ingredients,directions, image);
itemList.add(newObject);
receptDB.insertReceptItem(newObject);
//refreshArrayList();
}
}
private void refreshArrayList() {
ArrayList tempList = receptDB.getAllReceptItems();
itemList.clear();
itemList.addAll(tempList);
adapter.notifyDataSetChanged();
}
private void removeTaskAtPosition(int position) {
if (itemList.get(position) != null) {
receptDB.removeReceptItem(itemList.get(position));
refreshArrayList();
}
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
#Override
protected void onDestroy() {
super.onDestroy();
receptDB.close();
}
}
Logcat:
08-12 15:37:00.743 22879-22879/de.ur.mi.android.excercises.starter E/AndroidRuntime: FATAL EXCEPTION: main
Process: de.ur.mi.android.excercises.starter, PID: 22879
java.lang.RuntimeException: Unable to start activity ComponentInfo{de.ur.mi.android.excercises.starter/de.ur.mi.android.excercises.starter.List_Page}: java.lang.NullPointerException: Attempt to invoke virtual method 'long de.ur.mi.android.excercises.starter.DatabaseAdapter.insertReceptItem(de.ur.mi.android.excercises.starter.domain.ListItem)' on a null object reference
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2720)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2781)
at android.app.ActivityThread.-wrap12(ActivityThread.java)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1508)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:241)
at android.app.ActivityThread.main(ActivityThread.java:6274)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'long de.ur.mi.android.excercises.starter.DatabaseAdapter.insertReceptItem(de.ur.mi.android.excercises.starter.domain.ListItem)' on a null object reference
at de.ur.mi.android.excercises.starter.List_Page.addObject(List_Page.java:99)
at de.ur.mi.android.excercises.starter.List_Page.onCreate(List_Page.java:40)
at android.app.Activity.performCreate(Activity.java:6720)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1119)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2673)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2781) 
at android.app.ActivityThread.-wrap12(ActivityThread.java) 
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1508) 
at android.os.Handler.dispatchMessage(Handler.java:102) 
at android.os.Looper.loop(Looper.java:241) 
at android.app.ActivityThread.main(ActivityThread.java:6274) 
at java.lang.reflect.Method.invoke(Native Method) 
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886) 
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776) 

In your Activity's onCreate you are calling addObject() before calling setupDatabase(). Only inside setupDatabase() you are initialising receptDB instance.
But you are accessing that receptDb inside addObject() method.
receptDB.insertReceptItem(newObject);
So during that time, your receptDB has null reference and so you are getting NullPointerException.
So swap the below two lines from,
addObject();
setupDatabase();
to this:
setupDatabase();
addObject();

How to get Sum of SQLite Column by matching id

The app: I have an app that creates multiple machines with:
id, name and location
each of these machines I have to let the user input the income respectively.
The problem: I need to SUM all income(money, date, note, machines_id) inputted from each machine AND display it in a TextView in a different Activity.
My question: How do I get the data from the rawQuery of my getIncomeOfMachine method to another Activity?
What I tried: Using Bundles, Intents, SharedPreferences from the DBHelper class.
DBHelper
public class DBHelpter extends SQLiteOpenHelper {
private static final String DB_NAME = "machines.db";
private static final int DB_VERSION = 1;
public static final String TABLE_MACHINES = "machines";
public static final String MACHINES_COLUMN_NAME = "name";
public static final String MACHINES_COLUMN_LOCATION = "location";
public static final String MACHINES_ID = "id";
public static final String TABLE_INCOME = "income";
public static final String INCOME_COLUMN_MONEY = "money";
public static final String INCOME_COLUMN_DATE = "date";
public static final String INCOME_COLUMN_NOTE = "note";
public static final String INCOME_ID = "id";
public static final String INCOME_COLUMN_MACHINES_ID = "machines_id";
private Context mContext;
public DBHelpter(Context context) {
super(context, DB_NAME, null, DB_VERSION);
}
#Override
public void onCreate(SQLiteDatabase db) {
String query1 = String.format("CREATE TABLE " + TABLE_MACHINES + "("
+ MACHINES_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ MACHINES_COLUMN_NAME + " TEXT NOT NULL, "
+ MACHINES_COLUMN_LOCATION + " TEXT NOT NULL)",
TABLE_MACHINES, MACHINES_COLUMN_NAME, MACHINES_COLUMN_LOCATION, MACHINES_ID);
String query2 = String.format("CREATE TABLE " + TABLE_INCOME + "("
+ INCOME_ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
+ INCOME_COLUMN_MONEY + " REAL NOT NULL, "
+ INCOME_COLUMN_DATE + " DATE NOT NULL, "
+ INCOME_COLUMN_NOTE + " TEXT NOT NULL, "
+ INCOME_COLUMN_MACHINES_ID + " INTEGER NOT NULL)",
TABLE_INCOME, INCOME_ID, INCOME_COLUMN_MONEY, INCOME_COLUMN_DATE, INCOME_COLUMN_NOTE, INCOME_COLUMN_MACHINES_ID);
db.execSQL(query1);
db.execSQL(query2);
}
#Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String query1 = String.format("DROP TABLE IF EXISTS " + TABLE_MACHINES);
String query2 = String.format("DROP TABLE IF EXISTS " + TABLE_INCOME);
db.execSQL(query1);
db.execSQL(query2);
onCreate(db);
}
public void insertNewMachine(String name, String location){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(MACHINES_COLUMN_NAME, name);
values.put(MACHINES_COLUMN_LOCATION, location);
db.insertWithOnConflict(TABLE_MACHINES, null, values, SQLiteDatabase.CONFLICT_REPLACE);
db.close();
}
public void insertNewIncome(Double money, String date, String note, long machines_id){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(INCOME_COLUMN_MONEY, money);
values.put(INCOME_COLUMN_DATE, date);
values.put(INCOME_COLUMN_NOTE, note);
values.put(INCOME_COLUMN_MACHINES_ID, machines_id);
db.insertWithOnConflict(TABLE_INCOME, null, values, SQLiteDatabase.CONFLICT_REPLACE);
db.close();
}
public void getIncomeOfMachine(long machinesId){
SQLiteDatabase db = getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT machines_id, SUM(money) AS total FROM income WHERE machines_id = "+machinesId+"", null);
while (cursor.moveToFirst()){
String totalAmount = String.valueOf(cursor.getInt(0));
SharedPreferences mSharedPreferences = mContext.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor mEditor = mSharedPreferences.edit();
mEditor.putString("total_amount", totalAmount);
mEditor.commit();
}
cursor.close();
db.close();
}
public ArrayList<MachinesClass> getAllMachines(){
ArrayList<MachinesClass> machinesList = new ArrayList<>();
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM "+ TABLE_MACHINES, null);
while (cursor.moveToNext()){
final long id = cursor.getLong(cursor.getColumnIndex(MACHINES_ID));
final String name = cursor.getString(cursor.getColumnIndex(MACHINES_COLUMN_NAME));
final String location = cursor.getString(cursor.getColumnIndex(MACHINES_COLUMN_LOCATION));
machinesList.add(new MachinesClass(id, name, location));
}
cursor.close();
db.close();
return machinesList;
}
RecyclerViewAdapter
public class MachinesAdapter extends RecyclerView.Adapter<MachinesAdapter.ViewHolder> {
private ArrayList<MachinesClass> machinesList;
private LayoutInflater mInflater;
private DBHelpter mDBHelpter;
private Context mContext;
public static final String PREFS_NAME = "MyPrefsFile";
public MachinesAdapter(Context mContext, ArrayList<MachinesClass> machinesList){
this.mContext = mContext;
this.machinesList = machinesList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.machines_list, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, final int position) {
holder.mLocation.setText(machinesList.get(position).getLocation());
holder.v.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
SharedPreferences mSharedPreferences = mContext.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
SharedPreferences.Editor mEditor = mSharedPreferences.edit();
mEditor.putString("location", machinesList.get(position).getLocation());
mEditor.putLong("machines_id", machinesList.get(position).getId());
mEditor.commit();
Bundle bundle = new Bundle();
bundle.putString("location", machinesList.get(position).getLocation());
Intent intent = new Intent(v.getContext(), MachineInfo.class);
intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
intent.putExtras(bundle);
mContext.startActivity(intent);
}
});
}
#Override
public int getItemCount() {
return machinesList != null ? machinesList.size() : 0;
}
public class ViewHolder extends RecyclerView.ViewHolder {
public TextView mLocation, mMoney;
public LinearLayout mLinearLayout;
public View v;
public ViewHolder(View v) {
super(v);
mLinearLayout = (LinearLayout) v.findViewById(R.id.linearLayout);
mLocation = (TextView) v.findViewById(R.id.tvLocation);
mMoney = (TextView) v.findViewById(R.id.tvMoney);
this.v = v;
}
}
}
MachineInfo
public class MachineInfo extends AppCompatActivity {
private TextView mLocation, mMoney, mNotes;
private DBHelpter mDBHelpter;
private FloatingActionButton mFAB;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_machine_info);
mDBHelpter = new DBHelpter(getApplicationContext());
mLocation = (TextView) findViewById(R.id.tvLocation);
mMoney = (TextView) findViewById(R.id.tvMoney);
mNotes = (TextView) findViewById(R.id.tvNotes);
mFAB = (FloatingActionButton) findViewById(R.id.fabAddIncome);
SharedPreferences mSharedPreferences = getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
String total_amount = mSharedPreferences.getString("total_amount", null);
mMoney.setText(total_amount);
String location = mSharedPreferences.getString("location", null);
mLocation.setText(location);
mFAB.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), IncomeCreation.class);
startActivity(i);
}
});
}
}
If you need any other Activity or layout, let me know!

First, I suggest a change to getIncomeOfMachine(). Since this method is in DBHelper, it should only be responsible for interacting with the database. It should not know anything about SharedPreferences or Activity. Instead, it should return the value retrieved from the database and let the caller decide what to do with that value. Since you know there is only one row in the resulting Cursor, you do not need a loop. Just move to the first row, get the total, and return it.
Second, since you are only passing a single value to an activity, and you presumably do not need to store it permanently for later use, you should use an Intent rather than SharedPreferences. Starting Another Activity has a clear example of sending a value to another activity. If you have problems using this example in your app, feel free to post a new question showing what you did and explaining the problem you encountered.