public class DBHelper2  extends SQLiteOpenHelper {
public DBHelper2(Context context) {
    super(context, Constants.DB_NAME2, null, Constants.DB_VERSION);
}

@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL(Constants.CREATE_TB2);

}

@Override
public void onUpgrade(SQLiteDatabase db, int i, int i1) {
    db.execSQL(Constants.DROP_TB2);
    onCreate(db);
}
}

public class DBAdapter2 {
Context c;
SQLiteDatabase db;
DBHelper2 helper;

public DBAdapter2(Context c) {
    this.c = c;
    helper = new DBHelper2(c);
}


public void openDB2() {
    try {
        db = helper.getWritableDatabase();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}

public void closeDB2() {
    try {
        helper.close();
    } catch (SQLException e) {
        e.printStackTrace();
    }
}


//REGISTER
public boolean register(String username, String password) {
    try {
        ContentValues cv = new ContentValues();
        cv.put(Constants.USERNAME, username);
        cv.put(Constants.PASSWORD, password);
        long result = db.insert(Constants.TB_NAME2, Constants.ROW_ID2, cv);
        if (result > 0) {
            return true;
        }
    } catch (SQLException e) {
        e.printStackTrace();
    }
    return false;
}

public String getSinlgeEntry(String userName)
{
    Cursor cursor=db.query(Constants.DB_NAME2, null, Constants.USERNAME +"=?", new String[]{userName}, null, null, null);
    if(cursor.getCount()<1) // UserName Not Exist
    {
        cursor.close();
        return "NOT EXIST";
    }
    cursor.moveToFirst();
    String password= cursor.getString(cursor.getColumnIndex(Constants.PASSWORD));
    cursor.close();
    return password;
}

 }

public class Login extends AppCompatActivity {

Button btnSignIn,btnSignUp;
DBAdapter2 db;
EditText editTextUserName,editTextPassword;

@Override
protected void onCreate(Bundle savedInstanceState)
{
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login);
     editTextUserName=(EditText)findViewById(R.id.editTextUserNameToLogin);
    editTextPassword=(EditText)findViewById(R.id.editTextPasswordToLogin);
    // create a instance of SQLite Database
    db=new DBAdapter2(this);
    db.openDB2();

    // Get The Refference Of Buttons
    btnSignIn=(Button)findViewById(R.id.buttonSignIn);
    btnSignUp=(Button)findViewById(R.id.buttonRegister);

    // Set OnClick Listener on SignUp button
    btnSignUp.setOnClickListener(new View.OnClickListener() {
        public void onClick(View v) {
            // TODO Auto-generated method stub

            /// Create Intent for SignUpActivity  abd Start The Activity
            Intent intentSignUP=new Intent(getApplicationContext(),Register.class);
            startActivity(intentSignUP);
        }
    });
    btnSignIn.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // get The User name and Password
            String userName=editTextUserName.getText().toString();
            String password=editTextPassword.getText().toString();

            // fetch the Password form database for respective user name
            String storedPassword=db.getSinlgeEntry(userName);

            // check if the Stored password matches with  Password entered by user
            if(password.equals(storedPassword))
            {
                Toast.makeText(Login.this, "Congrats: Login Successfull", Toast.LENGTH_LONG).show();
                Intent intent = new Intent(Login.this,MainActivity.class);
                startActivity(intent);
            }
            else
            {
                Toast.makeText(Login.this, "User Name or Password does not match", Toast.LENGTH_LONG).show();
            }
        }
    });

}
@Override
protected void onDestroy() {
    super.onDestroy();
    // Close The Database
    db.closeDB2();
}

public class Constants {
    //columns

static final String ROW_ID="id";
static final String ROW_ID2="id2";

static final String NAME="name";
static final String NUMBER="number";
static final String USERNAME ="username";
static  final String PASSWORD = "password";


//properties
static final String DB_NAME="hh_DB";
static final String DB_NAME2="hh2_DB";

static final String TB_NAME="hh_TB";
static final String TB_NAME2="hh2_TB";

static final int DB_VERSION=1;

//creating tb
static final String CREATE_TB="CREATE TABLE hh_TB(id INTEGER PRIMARY KEY AUTOINCREMENT,"
        + "name TEXT NOT NULL," + "number TEXT NOT NULL );";
static final String CREATE_TB2="CREATE TABLE hh2_TB(id2 INTEGER PRIMARY KEY AUTOINCREMENT,"
       + "username TEXT NOT NULL ," + "password TEXT NOT NULL);";


//DROP TB
static final String DROP_TB="DROP TABLE IF EXISTS " +TB_NAME;
static final String DROP_TB2="DROP TABLE IF EXISTS " +TB_NAME2;

android.database.sqlite.SQLiteException: no such table: hh2_DB (code 1): , while compiling: SELECT * FROM hh2_DB WHERE username=?
                                                 at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
                                                 at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:889)
                                                 at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:500)
                                                 at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
                                                 at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
                                                 at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
                                                 at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
                                                 at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
                                                 at android.database.sqlite.SQLiteDatabase.queryWithFactory(SQLiteDatabase.java:1161)
                                                 at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1032)
                                                 at android.database.sqlite.SQLiteDatabase.query(SQLiteDatabase.java:1200)
                                                 at com.example.mike.phonebook3.mDataBase.DBAdapter2.getSinlgeEntry(DBAdapter2.java:59)
                                                 at com.example.mike.phonebook3.Login$2.onClick(Login.java:53)
                                                 at android.view.View.performClick(View.java:4443)
                                                 at android.view.View$PerformClick.run(View.java:18443)
                                                 at android.os.Handler.handleCallback(Handler.java:733)
                                                 at android.os.Handler.dispatchMessage(Handler.java:95)
                                                 at android.os.Looper.loop(Looper.java:136)
                                                 at android.app.ActivityThread.main(ActivityThread.java:5001)
                                                 at java.lang.reflect.Method.invokeNative(Native Method)
                                                 at java.lang.reflect.Method.invoke(Method.java:515)
                                                 at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:801)
                                                 at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:617)
                                                 at dalvik.system.NativeStart.main(Native Method)