I am new to Android and I am working on a simple quiz application.
There are 3 options and 1 Question.
Questions and options are stored in a database.
What I want to do that when the application starts it shows the first question and answer and on click of right or wrong answer it updates the questions and options. Means show the next question and options.
So right now I can successfully show the first questions and relative options on screen but on the click, it doesn't show the next question.
When I try to find the problem I found that the code I am using is only showing the first value after executing the query while there are more rows of results.
I try to change the value of the index in getstring() from 1 to 2 and 0 but there is no result.
So my question is how can I achieve this task.
Here is my code.
package com.example.android.quiz_app_androidmodule;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.os.AsyncTask;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
public class MainActivity extends AppCompatActivity {
ConnectionClass connectionClass;
TextView Question, Score;
Button btnlogin, btnA, btnB, btnC, btnStart;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
connectionClass = new ConnectionClass();
btnlogin = (Button) findViewById(R.id.btnStart);
btnA = (Button) findViewById(R.id.button1);
btnB = (Button) findViewById(R.id.button2);
btnC = (Button) findViewById(R.id.button3);
Question = (TextView) findViewById(R.id.textViewQuestion);
Score = (TextView) findViewById(R.id.textViewScore);
btnlogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
DoLogin doLogin = new DoLogin();
doLogin.execute("");
btnA.setVisibility(View.VISIBLE);
btnB.setVisibility(View.VISIBLE);
btnC.setVisibility(View.VISIBLE);
Question.setVisibility(View.VISIBLE);
Score.setVisibility(View.VISIBLE);
btnlogin.setVisibility(View.GONE);
}
});
}
String z = "";
String zA = "";
String zB="";
String zC="";
int id = 1;
int points;
public class DoLogin extends AsyncTask<String, String, String> {
Boolean isSuccess = false;
@Override
protected void onPostExecute(String r) {
if (isSuccess) {
Question.setText(z);
btnA.setText(zA);
btnB.setText(zB);
btnC.setText(zC);
}
}
@Override
protected String doInBackground(String... params) {
try {
Connection con = connectionClass.CONN();
if (con == null) {
z = "Error in connection with SQL server";
} else {
String query = "select question from Question where quizID >= '0'";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
String queryA = "select optionOne from Options where quizID >= '0'";
Statement stmtA = con.createStatement();
ResultSet rsA = stmtA.executeQuery(queryA);
String queryB = "select optionTwo from Options where quizID >= '0'";
Statement stmtB = con.createStatement();
ResultSet rsB = stmtB.executeQuery(queryB);
String queryC = "select optionThree from Options where quizID >= '0'";
Statement stmtC = con.createStatement();
ResultSet rsC = stmtC.executeQuery(queryC);
if (rs.next() | rsA.next() | rsB.next() | rsC.next()) {
z = rs.getString(id).toString();
zA=rsA.getString(id).toString();
zB=rsB.getString(id).toString();
zC=rsC.getString(id).toString();
isSuccess = true;
}
else {
z = "Invalid Credentials";
isSuccess = false;
}
}
} catch (Exception ex) {
isSuccess = false;
z = "Exceptions";
}
return z;
}
}
}
I am trying to use as simple code, to access the data, as I can.
Please let me know if someone needs more info.
My logic was: I'll update the 'id' variable and execute the method again and it'll update the views with new values.
By the way, I am using Buttons to show the options. Database is in MS SQL Server. Please guide.
You should add first AsyncTask call just before initializing the views and then on each next button click you should increment id by 1.
package com.example.android.quiz_app_androidmodule;
import android.support.v7.app.AppCompatActivity;import android.os.Bundle;
import android.os.AsyncTask;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.Statement;
public class MainActivity extends AppCompatActivity {
ConnectionClass connectionClass;
TextView Question, Score;
Button btnlogin, btnA, btnB, btnC, btnStart;
DoLogin doLogin ;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
connectionClass = new ConnectionClass();
btnlogin = (Button) findViewById(R.id.btnStart);
btnA = (Button) findViewById(R.id.button1);
btnB = (Button) findViewById(R.id.button2);
btnC = (Button) findViewById(R.id.button3);
Question = (TextView) findViewById(R.id.textViewQuestion);
Score = (TextView) findViewById(R.id.textViewScore);
doLogin.execute(id);
btnlogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
//Make sure your first id is 1;
id = id+1;
dologin = = new DoLogin()
doLogin.execute(id);
btnA.setVisibility(View.VISIBLE);
btnB.setVisibility(View.VISIBLE);
btnC.setVisibility(View.VISIBLE);
Question.setVisibility(View.VISIBLE);
Score.setVisibility(View.VISIBLE);
btnlogin.setVisibility(View.GONE);
}
});
}
String z = "";
String zA = "";
String zB="";
String zC="";
int id = 0;
int points;
public class DoLogin extends AsyncTask<String, String, String> {
Boolean isSuccess = false;
@Override
protected void onPostExecute(String r) {
if (isSuccess) {
Question.setText(z);
btnA.setText(zA);
btnB.setText(zB);
btnC.setText(zC);
}
}
@Override
protected String doInBackground(String... params) {
String id = params[0];
try {
Connection con = connectionClass.CONN();
if (con == null) {
z = "Error in connection with SQL server";
} else {
String query = "select question from Question where quizID >= "+id;
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
String queryA = "select optionOne from Options where quizID >= "+id;
Statement stmtA = con.createStatement();
ResultSet rsA = stmtA.executeQuery(queryA);
String queryB = "select optionTwo from Options where quizID >= "+id;
Statement stmtB = con.createStatement();
ResultSet rsB = stmtB.executeQuery(queryB);
String queryC = "select optionThree from Options where quizID >= "+id;
Statement stmtC = con.createStatement();
ResultSet rsC = stmtC.executeQuery(queryC);
if (rs.next() | rsA.next() | rsB.next() | rsC.next()) {
z = rs.getString(id).toString();
zA=rsA.getString(id).toString();
zB=rsB.getString(id).toString();
zC=rsC.getString(id).toString();
isSuccess = true;
}
else {
z = "Invalid Credentials";
isSuccess = false;
}
}
} catch (Exception ex) {
isSuccess = false;
z = "Exceptions";
}
return z;
}
}
}