How to put data from sqllite into a listview? - sqlite

Question

I have an app where a user can put in three inputs (name, quantity and type) I want the input to go into the database and then when the user clicks the status button then they can view all of the user inputs in a listview. In my case when i run the app the items get added to the database but then when i click to view them in the inventorystatus activity the app exits off. Does anyone know where I have gone wrong or what im missing? It might be a stupid question im new to this sorry.
DatabaseHelperUser class:
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "Inventory.db";
public static final String TABLE_NAME = "Inventory_table";
public static final String COL1 = "Name";
public static final String COL2 = "Quantity";
public static final String COL3 = "Type";
public DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, 1);
}
#Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_NAME + " (Name TEXT, Quantity Text, Type Text)");
}
#Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
onCreate(db);
}
public boolean insertData(String Name, String Quantity, String Type){
SQLiteDatabase db = this.getWritableDatabase();
ContentValues contentValues = new ContentValues();
contentValues.put(COL1, Name);
contentValues.put(COL2, Quantity);
contentValues.put(COL3, Type);
long result = db.insert(TABLE_NAME, null, contentValues);
if(result == -1)
return false;
else
return true;
}
public Cursor getAllData(){
SQLiteDatabase db = this.getWritableDatabase();
Cursor data = db.rawQuery("select * from " + TABLE_NAME, null);
return data;
}
public String deletedata(){
SQLiteDatabase myDB = this.getWritableDatabase();
myDB.delete(TABLE_NAME, null, null);
myDB.close();
return null;
}
}
AddItem Class:
public class AddItem extends AppCompatActivity {
DatabaseHelper myDB;
EditText etName, etQuantity, etType;
Button btAdd2, btStatus2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_add_item);
myDB = new DatabaseHelper(this);
final EditText etName = findViewById(R.id.editTextName);
final EditText etQuantity = findViewById(R.id.editTextQuantity);
final RadioButton rbBiscuit = findViewById(R.id.radioButtonBiscuit);
final RadioButton rbCookie = findViewById(R.id.radioButtonCookie);
final RadioButton rbCake = findViewById(R.id.radioButtonCake);
final RadioButton rbIngredient = findViewById(R.id.radioButtonIngredient);
final RadioButton rbOther = findViewById(R.id.radioButtonOther);
Button btAdd2 = findViewById(R.id.buttonAdd2);
final Button btStatus2 = findViewById(R.id.buttonStatus2);
final EditText etType = findViewById(R.id.editTextType1);
btAdd2.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String edtName = etName.getText().toString();
String edtQuantity = etQuantity.getText().toString();
String edtType = etType.getText().toString();
if (etName.length() !=0 || etQuantity.length() !=0 || etType.length() !=0){
// myDB.insertData(edtName, edtQuantity, edtType);
AddData(edtName, edtQuantity, edtType);
etName.setText("");
etQuantity.setText("");
etType.setText("");
}
else{
Toast.makeText(AddItem.this, "Fill in all of the fields", Toast.LENGTH_SHORT).show();
}
}
public void AddData(String edtName, String edtQuantity, String edtType){
boolean insert = myDB.insertData(edtName, edtQuantity, edtType);
if(insert){
Toast.makeText(AddItem.this, "Data Inserted", Toast.LENGTH_SHORT).show();
}
else{
Toast.makeText(AddItem.this, "Error, Data not Inserted", Toast.LENGTH_SHORT).show();
}
}
});
btStatus2.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
Intent i = new Intent(AddItem.this, InventoryStatus.class);
startActivity(i);
}
});
}
}
InventoryStatus class:
public class InventoryStatus extends AppCompatActivity {
DatabaseHelper myDB;
ListView listView;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_inventory_status);
ListView listView = findViewById(R.id.listViewStock);
myDB = new DatabaseHelper(this);
populateListView();
}
public void populateListView(){
Cursor data = myDB.getAllData();
ArrayList<String> list = new ArrayList<>();
while(data.moveToNext()){
list.add(data.getString(1));
}
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1);
listView.setAdapter(adapter);
}
}

Answer 1

You forgot to pass list to adapter constructor.
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, **list**);
And try type-casting listview in InventoryStatus.class as:
ListView listView = (ListView) findViewById(R.id.listViewStock);