Database Develop

Insert data to database SQlite

I want to insert data to a database I have created. I have created an insert command at the OnCreate class. When viewing the database in SQLite Browser the data do not show. Can anyone help me
DatabaseHelper
Code:
package app.mobiledevicesecurity;
import android.content.ContentValues;
import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
/**
* Created by Martin on 2015/07/28.
*/
public class DatabaseHelper extends SQLiteOpenHelper {
public static final String DATABASE_NAME = "mobilesec.db";
public static final String TABLE_NAME = "read_table";
public static final String COL_1 = "ID";
public static final String COL_2 = "CATEGORY";
public static final String COL_3 = "HEADING";
public static final String COL_4 = "INFO";
public DatabaseHelper(Context context) {
super(context, DATABASE_NAME, null, 1);
SQLiteDatabase db = this.getWritableDatabase();
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("create table " + TABLE_NAME + " (ID INTEGER PRIMARY KEY AUTOINCREMENT, CATEGORY TEXT, HEADING TEXT, INFO TEXT)");
ContentValues cv = new ContentValues();
cv.put(COL_2,"Malware");
cv.put(COL_3,"Virus");
cv.put(COL_4,"Harmfull for device");
db.insert(TABLE_NAME, null, cv);
}
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
onCreate(db);
}
}
MainActivity
Code:
package app.mobiledevicesecurity;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
public class MainActivity extends ActionBarActivity {
DatabaseHelper myDb;
private static Button readbtn;
private static Button quizbtn;
private static Button scoresbtn;
private static Button settingsbtn;
private static Button helpbtn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
myDb = new DatabaseHelper(this);
OnClickReadButtonListener();
OnClickQuizButtonListener();
OnClickScoresButtonListener();
OnClickSettingsButtonListener();
OnClickHelpButtonListener();
}
public void OnClickReadButtonListener() {
readbtn = (Button) findViewById(R.id.readbutton);
readbtn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("app.mobiledevicesecurity.Read_Category");
startActivity(intent);
}
}
);
}
public void OnClickQuizButtonListener() {
quizbtn = (Button) findViewById(R.id.quizbutton);
quizbtn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("app.mobiledevicesecurity.Quiz");
startActivity(intent);
}
}
);
}
public void OnClickScoresButtonListener() {
scoresbtn = (Button) findViewById(R.id.scoresbutton);
scoresbtn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("app.mobiledevicesecurity.Scores");
startActivity(intent);
}
}
);
}
public void OnClickSettingsButtonListener() {
settingsbtn = (Button) findViewById(R.id.settingsbutton);
settingsbtn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("app.mobiledevicesecurity.Settings");
startActivity(intent);
}
}
);
}
public void OnClickHelpButtonListener() {
helpbtn = (Button) findViewById(R.id.helpbutton);
helpbtn.setOnClickListener(
new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent("app.mobiledevicesecurity.Help");
startActivity(intent);
}
}
);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
when I run the app on the emulator and open Android Device Monitor and get the database file and open it with SQlite Browser. Only the Column names are created the values are not shown. Why is this happening

Try to commit after you insert a record, also I think you can check what the insert command is returning to see if the insert command was successful or not...

The reason it isn't working is because you probably added the the insert after you had already created your database, so therefore onCreate is not being called anymore.
onUpgrade will only be called if you change the version of your database, so that will not be called either.
you should just make another method that is used to update your table, or explicitly call Oncreate.
what I did while I was testing is in the constructor of my database class, i would call a method that would drop all the tables, and then explicitly call onCreate after that. Remove this code when you are done testing

Help with grid View

Hello!
i need some help, i am creating a Grid View with this java code:
MainActivity
public class MainActivity extends AppCompatActivity {
private GridView gridView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
gridView = (GridView)findViewById(R.id.gridview);
gridView.setAdapter(new GridAdapter(this));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
Click to expand...
Click to collapse
Product
public class Product {
private static String nombrePizza;
private static String ingredientesPizza;
private static int imagenPizza;
private static int idThumbnail;
public Product(String nombrePizza, String ingredientesPizza, int imagenPizza){
this.nombrePizza = nombrePizza;
this.ingredientesPizza = ingredientesPizza;
this.imagenPizza = imagenPizza;
}
public String getNombrePizza(){return nombrePizza;}
public String getIngredientesPizza(){return ingredientesPizza;}
public int getImagenPizza(){return imagenPizza;}
public int getId(){return nombrePizza.hashCode();}
public static Product[] Pizzas={
new Product(
"Proscuito",
"Jamon York y queso",
R.drawable.imagenprueba),
new Product(
"Tropical",
"Jamon York, queso y piña",
R.drawable.imagenprueba),
new Product(
"Barbacoa",
"Carne picada, queso y salsa Barbacoa",
R.drawable.imagenprueba),
new Product(
"Romana",
"Jamon York, champiñones y queso",
R.drawable.cubo),
};
public static Product getItem(int id) {
for (Product item : Pizzas) {
if (item.getId() == id) {
return item;
}
}
return null;
}
}
Click to expand...
Click to collapse
Grid Adapter
public class GridAdapter extends BaseAdapter {
private final Context mContext;
public GridAdapter(Context c){
this.mContext = c;
}
@Override
public int getCount(){return Product.Pizzas.length;}
@Override
public Product getItem(int position){return Product.Pizzas[position];}
@Override
public long getItemId(int position){return 0;}
@Override
public View getView(int position, View ConvertView, ViewGroup viewGroup){
if(ConvertView == null){
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
ConvertView = inflater.inflate(R.layout.grid_item, viewGroup, false);
}
TextView name = (TextView)ConvertView.findViewById(R.id.grid_mainText);
ImageView image = (ImageView) ConvertView.findViewById(R.id.grid_image);
TextView descripcion = (TextView) ConvertView.findViewById(R.id.grid_subText);
final Product item = getItem(position);
image.setImageResource(item.getImagenPizza());
name.setText(item.getNombrePizza());
descripcion.setText(item.getIngredientesPizza());
return ConvertView;
}
}
Click to expand...
Click to collapse
It work fine except for one thing, the app only shows the last product of the java code (Pizza romana)four times
I dont know why my app do this, can somebody help me??
Thank you! :fingers-crossed:

Executing code in 2end activity

Hi .
I'm newbie so I need your help in some issue
I'm coding an app that has 2 activity .
The problem is I want Some codes to be execute right after user goes to 2end activity .
So I write the codes in Oncreate function . but in test when user goes to 2end activity he will see just empty design of activity . like I didn't write any code for that :/
Please help me what should I do .
p.n : I want 2end activity to show the inbox content to user and I'm sure that my codes is correct .
sry for my bad english .

You need to display all your codes.

hiphop12ism said:
You need to display all your codes.
Click to expand...
Click to collapse
Activity A
Code:
public class A extends Activity implements View.OnClickListener {
Button inbox,draft,sent,call;
TextView lblmsg,lblNumber;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_a);
inbox = (Button) findViewById(R.id.btn1);
sent = (Button) findViewById(R.id.btn2);
draft = (Button) findViewById(R.id.btn3);
call = (Button) findViewById(R.id.btn4);
inbox.setOnClickListener(this);
draft.setOnClickListener(this);
call.setOnClickListener(this);
sent.setOnClickListener(this);
}
@Override
public void onClick(View v) {
if (v == inbox) {
Intent i;
i = new Intent(this, B.class);
startActivity(i);
}
}
Activity B
Code:
public class B extends AppCompatActivity {
ListView lv1;
SimpleCursorAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_b);
lv1=(ListView)findViewById(R.id.lv);
Uri InboxUri= Uri.parse("Content://sms/inbox");
String [] C= new String[] { "_id", "address", "body" };
ContentResolver cr=getContentResolver();
Cursor D = cr.query(InboxUri, C, null, null, null);
adapter = new SimpleCursorAdapter(
this,
R.layout.row,
D,
new String[]{"body","address"},
new int[]{R.id.lblmsg,R.id.lblNumber});
lv1.setAdapter(adapter);
}
and I forgot to say Android studio detecting no error

Using Intent(send mail) in Navigation drawer

I want to send mail from Navigation Drawer using the intent. First, my MainActivity.
Code:
else if(id==R.id.nav_mail) {
fragment = new MailFragment();
}
and MailFragment.
Code:
public class MailFragment extends Fragment {
public MailFragment() {
Intent email = new Intent(Intent.ACTION_SEND);
email.setType("plain/text");
String[] address = {"********@gmail.com"};
email.putExtra(Intent.EXTRA_EMAIL, address);
email.putExtra(Intent.EXTRA_SUBJECT, "Subject___****");
email.putExtra(Intent.EXTRA_TEXT, "Text___****.\n\n");
startActivity(email);
}
// @Override
// public View onCreateView(LayoutInflater inflater, ViewGroup container,
// Bundle savedInstanceState) {
// TextView textView = new TextView(getActivity());
// textView.setText(R.string.hello_blank_fragment);
// return textView;
// }
}
Run to create crash. The reason why I used to use fragment is because I made the simple screen change function fragment.
If you need more code, comment plz.

I didn't get what you are trying to do. If you are trying to invoke the "Select your mail app" screen and then send a message thru the Intent all of this when the user clicks on a row on the drawer then you should just copy the code to
Code:
else if(id==R.id.nav_mail) {
// here
}
without switching any fragment.
By the way, as far as I know, the fragment's public constructor must be empty.

You cannot do it from Fragment's constructor. Move your code to onActivityCreated() method.

qlife1146 said:
I want to send mail from Navigation Drawer using the intent. First, my MainActivity.
Code:
else if(id==R.id.nav_mail) {
fragment = new MailFragment();
}
and MailFragment.
Code:
public class MailFragment extends Fragment {
public MailFragment() {
Intent email = new Intent(Intent.ACTION_SEND);
email.setType("plain/text");
String[] address = {"********@gmail.com"};
email.putExtra(Intent.EXTRA_EMAIL, address);
email.putExtra(Intent.EXTRA_SUBJECT, "Subject___****");
email.putExtra(Intent.EXTRA_TEXT, "Text___****.\n\n");
startActivity(email);
}
// @Override
// public View onCreateView(LayoutInflater inflater, ViewGroup container,
// Bundle savedInstanceState) {
// TextView textView = new TextView(getActivity());
// textView.setText(R.string.hello_blank_fragment);
// return textView;
// }
}
Run to create crash. The reason why I used to use fragment is because I made the simple screen change function fragment.
If you need more code, comment plz.
Click to expand...
Click to collapse
Creating a new Intent in the constructor is a really bad idea. An example from the android's developer guide
Code:
public class MainActivity extends AppCompatActivity {
public static final String EXTRA_MESSAGE = "com.example.myfirstapp.MESSAGE";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
/** Called when the user taps the Send button */
public void sendMessage(View view) {
Intent intent = new Intent(this, DisplayMessageActivity.class);
EditText editText = (EditText) findViewById(R.id.editText);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}
}

Runtime error when logging off android stuido mobile app

I have a java mobile app that is connected with Firebase, login and registration works perfect. I only get an error when I try to logout from the Home Page/Activity. This is the error i get and I don't know what to do.
Attempt to invoke virtual method 'java.lang.String com.google.firebase.auth.FirebaseUser.getUid()' on a null object reference at com.example.platformapp.HomeActivity.onCreate(HomeActivity.java:37)
This is my code for the Home Activity/Page
public class HomeActivity extends AppCompatActivity {
Button btnLogout;
FirebaseAuth myFireBaseAuth;
TextView email;
FirebaseFirestore myfStore;
String userID;
private FirebaseAuth.AuthStateListener myAuthStateListener;
@override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_home);
email = findViewById(R.id.displayEmail);
myFireBaseAuth = FirebaseAuth.getInstance();
myfStore = FirebaseFirestore.getInstance();
userID = myFireBaseAuth.getCurrentUser().getUid(); // This is line 37
DocumentReference documentReference = myfStore.collection("users").document(userID);
documentReference.addSnapshotListener(this, new EventListener<DocumentSnapshot>() {
@override
public void onEvent @nullable DocumentSnapshot documentSnapshot, @nullable FirebaseFirestoreException e) {
email.setText(documentSnapshot.getString("email"));
}
});
}
public void logout(View view)
{
FirebaseAuth.getInstance().signOut();
startActivity(new Intent(getApplicationContext(),LoginActivity.class));
finish();
}