Login multi user Android studio MySQL

In this chapter , we are going to explain, how you can integrate PHP and MYSQL with your android application. This is very useful in case you have a webserver, and you want to access its data on your android application.

MYSQL is used as a database at the webserver and PHP is used to fetch data from the database. Our application will communicate with the PHP page with necessary parameters and PHP will contact MYSQL database and will fetch the result and return the results to us.

PHP - MYSQL

Creating Database

MYSQL database can be created easily using this simple script. The CREATE DATABASE statement creates the database.

Creating Tables

Once database is created, its time to create some tables in the database. The CREATE TABLE statement creates the database.

Inserting Values in tables

When the database and tables are created. Now its time to insert some data into the tables. The Insert Into statement creates the database.

PHP - GET and POST methods

PHP is also used to fetch the record from the mysql database once it is created. In order to fetch record some information must be passed to PHP page regarding what record to be fetched.

The first method to pass information is through GET method in which $_GET command is used. The variables are passed in the url and the record is fetched. Its syntax is given below −

The second method is to use POST method. The only change in the above script is to replace $_GET with $_POST. In Post method, the variables are not passed through URL.

Android - Connecting MYSQL

Connecting Via Get Method

There are two ways to connect to MYSQL via PHP page. The first one is called Get method. We will use HttpGet and HttpClient class to connect. Their syntax is given below −

URL url = new URL(link);
HttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet();
request.setURI(new URI(link));

After that you need to call execute method of HttpClient class and receive it in a HttpResponse object. After that you need to open streams to receive the data.

HttpResponse response = client.execute(request);
BufferedReader in = new BufferedReader
(new InputStreamReader(response.getEntity().getContent()));

Connecting Via Post Method

In the Post method, the URLEncoder,URLConnection class will be used. The urlencoder will encode the information of the passing variables. It's syntax is given below −

URL url = new URL(link);
String data  = URLEncoder.encode("username", "UTF-8") 
+ "=" + URLEncoder.encode(username, "UTF-8");
data += "&" + URLEncoder.encode("password", "UTF-8") 
+ "=" + URLEncoder.encode(password, "UTF-8");
URLConnection conn = url.openConnection(); 

The last thing you need to do is to write this data to the link. After writing, you need to open stream to receive the responded data.

OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream()); 
wr.write( data ); 
BufferedReader reader = new BufferedReader(new 
InputStreamReader(conn.getInputStream()));			

Example

The below example is a complete example of connecting your android application with MYSQL database via PHP page. It creates a basic application that allows you to login using GET and POST method.

PHP - MYSQL part

In this example a database with the name of temp has been created at 000webhost.com. In that database, a table has been created with the name of table1. This table has three fields. (Username, Password, Role). The table has only one record which is ("admin","admin","administrator").

The php page has been given below which takes parameters by post method.

Android Part

To experiment with this example , you need to run this on an actual device on which wifi internet is connected.

Here is the content of src/com.example.phpmysql/MainActivity.java.

package com.example.phpmysql;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class MainActivity extends Activity {

   private EditText usernameField,passwordField;
   private TextView status,role,method;

   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);

      usernameField = (EditText)findViewById(R.id.editText1);
      passwordField = (EditText)findViewById(R.id.editText2);

      status = (TextView)findViewById(R.id.textView6);
      role = (TextView)findViewById(R.id.textView7);
      method = (TextView)findViewById(R.id.textView9);
   }



   public void login(View view){
      String username = usernameField.getText().toString();
      String password = passwordField.getText().toString();
      method.setText("Get Method");
      new SigninActivity(this,status,role,0).execute(username,password);

   }

   public void loginPost(View view){
      String username = usernameField.getText().toString();
      String password = passwordField.getText().toString();
      method.setText("Post Method");
      new SigninActivity(this,status,role,1).execute(username,password);
   }
}

Here is the content of src/com.example.phpmysql/SigninActivity.java.

Add the following content to build.gradle and rebuild the whole project.

Here is the content of activity_main.xml.

Here is the content of Strings.xml.

Here is the content of AndroidManifest.xml.

Let's try to run your PHPMYSQL application. I assume you have connected your actual Android Mobile device with your computer. To run the app from Android studio, open one of your project's activity files and click Run

Select your mobile device as an option and then check your mobile device which will display following screen −

Now just type in your username and password. In my case i am typing admin as username and password. It is shown in the figure −

Now press the Get button and wait a few seconds and response will be downloaded and will be shown to you. In this case, the response is the ROLE that is fetched in case of admin as username and password.It is shown in the figure below −

How do I login as a different user in MySQL?

Does MySQL support multiple users?

Can we connect MySQL with android studio?

How use xampp Android application?