Android MySQL Tutorial to Perform Basic CRUD Operation

January 6, 2021October 24, 2015 by Belal Khan

Hello friends, Here is another Android MySQL Tutorial, in this post we will learn the basic CRUD operation in MySQL database from Android Application. So without wasting time lets start our Android MySQL Tutorial.

What is CRUD?

I guess many of you already know that what is CRUD. But if anyone don’t know, CRUD is an Acronym for the Basic Database Operations. In any database we do the following basic operations.

Creating a Record -> In the database we insert a record.
Reading Stored Records -> No point of saving data when we can’t read it back 😛 (LOL). So the second operation is reading the stored data back.
Updating Stored Records -> We may also need to update the existing data. So the third operation is update.
Deleting Records -> Lastly we may also need to delete the existing data from the database.

So basically in any database we perform the above mentioned operations. In this tutorial I am going to use MySQL and PHP.

Why PHP and MySQL and Why Not SQLite?

Android gives us a feature of SQLite to use as the RDBMS for our app. But we can’t use SQLite only if we are building an app. This is because we need a centralize server. SQLite is local for every device so if a user is using your application you will not be able manage your users if it is only in SQLite. That is why we need a centralize database where we can store our app data.

If you want to learn about the SQLite using the Latest Architecture Component ROOM. Then here is a complete FREE COURSE for Android Room Database.

Do we have only PHP and MySQL for this?

Obviously NO? You can use any server side scripting language or database application. I am using here PHP and MySQL because it is easily available and I already know it. 😛 (LOL) But if you are an expert in Python or JAVA or NodeJS or basically any other technology then you can go with it. It will change only the server side coding. Android part will always be the same.

Building Web APIs

The first step is building the required Web APIs. This is because from the android application, to communicate with our web server we need an interface called API.

So our android device will send a request to our API, then our API will perform the requested task and it will give us the response related to the task. You can see the below diagram for more clarification.

The response that the web server gives should be in a standard structure, so that in our android side we can easily parse and get the information from the structure. For this everyone now uses JSON. If you heard this term for the first time then you should consider watching this 7 minute quick JSON tutorial.

I guess you got a basic idea about the task that we are going to do in this tutorial.

Creating Database

It is obvious that we need a database first 😛 . So here I am using XAMPP (You can go with wamp or lamp as well). So first create the following database.

So open localhost/phpmyadmin and run the following query to create the above table.

-- created by Belal Khan

-- website: www.simplifiedcoding.net

-- tables

-- Table: heroes

CREATE TABLE heroes (

id int NOT NULL AUTO_INCREMENT,

name varchar(200) NOT NULL,

realname varchar(200) NOT NULL,

rating int NOT NULL,

teamaffiliation varchar(100) NOT NULL,

CONSTRAINT heroes_pk PRIMARY KEY (id)

);

-- End of file.

Creating PHP Project

Now to perform the Database Operations we will create a PHP Project.

So inside htdocs (c:/xampp/htdocs) create a new folder (You can also use an IDE like PHP Storm to create project but remember create the project inside c:/xampp/htdocs only).
I have given the name HeroApi to my project. You can give any name. But I would say give the same name or else you may lead up to some errors following the post if you are a newbie.
Inside the project create two more folders named includes and Api. You can see the below screenshot for the directory structure that I am using. (I am using Sublime Text for coding server part).

You see we have four php files (3 inside includes and 1 inside v1). So you create these files as well.

Project Structure

So we have the following things in our PHP project.
- includes
  - Constants.php: In this file we will define all the required constants e.g., database name, username, password etc.
  - DbConnect.php: This fill will contain a class where we will connect to our MySQL database.
  - DbOperation.php: The actual CRUD operation is performed inside this file.
- v1
  - Api.php: This is our API, we will send request to this file only from the android side. And this file will handle all the API calls.

Defining Constants

First come inside the file Constants.php and write the following code.

<?php

* Created by Belal Khan

* website: www.simplifiedcoding.net

define('DB_HOST', 'localhost');

define('DB_USER', 'root');

define('DB_PASS', '');

define('DB_NAME', 'android');

Connecting to Database

Now inside DbConnect.php write the following code. I have explained the code using comments.

<?php

* Created by Belal Khan

* website: www.simplifiedcoding.net

//Class DbConnect

class DbConnect

{

//Variable to store database link

private $con;

//Class constructor

function __construct()

{

}

//This method will connect to the database

function connect()

{

//Including the constants.php file to get the database constants

include_once dirname(__FILE__) . '/Constants.php';

//connecting to mysql database

$this->con = new mysqli(DB_HOST, DB_USER, DB_PASS, DB_NAME);

//Checking if any error occured while connecting

if (mysqli_connect_errno()) {

echo "Failed to connect to MySQL: " . mysqli_connect_error();

}

//finally returning the connection link

return $this->con;

}

Performing Database Operations

Now we will do the CRUD operation inside the DbOperation.php file.

<?php

class DbOperation

{

//Database connection link

private $con;

//Class constructor

function __construct()

{

//Getting the DbConnect.php file

require_once dirname(__FILE__) . '/DbConnect.php';

//Creating a DbConnect object to connect to the database

$db = new DbConnect();

//Initializing our connection link of this class

//by calling the method connect of DbConnect class

$this->con = $db->connect();

}

* The create operation

* When this method is called a new record is created in the database

function createHero($name, $realname, $rating, $teamaffiliation){

$stmt = $this->con->prepare("INSERT INTO heroes (name, realname, rating, teamaffiliation) VALUES (?, ?, ?, ?)");

$stmt->bind_param("ssis", $name, $realname, $rating, $teamaffiliation);

if($stmt->execute())

return true;

return false;

}

* The read operation

* When this method is called it is returning all the existing record of the database

function getHeroes(){

$stmt = $this->con->prepare("SELECT id, name, realname, rating, teamaffiliation FROM heroes");

$stmt->execute();

$stmt->bind_result($id, $name, $realname, $rating, $teamaffiliation);

$heroes = array();

while($stmt->fetch()){

$hero = array();

$hero['id'] = $id;

$hero['name'] = $name;

$hero['realname'] = $realname;

$hero['rating'] = $rating;

$hero['teamaffiliation'] = $teamaffiliation;

array_push($heroes, $hero);

}

return $heroes;

}

* The update operation

* When this method is called the record with the given id is updated with the new given values

function updateHero($id, $name, $realname, $rating, $teamaffiliation){

$stmt = $this->con->prepare("UPDATE heroes SET name = ?, realname = ?, rating = ?, teamaffiliation = ? WHERE id = ?");

$stmt->bind_param("ssisi", $name, $realname, $rating, $teamaffiliation, $id);

if($stmt->execute())

return true;

return false;

}

* The delete operation

* When this method is called record is deleted for the given id

function deleteHero($id){

$stmt = $this->con->prepare("DELETE FROM heroes WHERE id = ? ");

$stmt->bind_param("i", $id);

if($stmt->execute())

return true;

return false;

}

Handling API Calls

Now here come the main part, which is handling the API calls. So come inside the Api.php which is inside the v1 folder.

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<?php

//getting the dboperation class

require_once '../includes/DbOperation.php';

//function validating all the paramters are available

//we will pass the required parameters to this function

function isTheseParametersAvailable($params){

//assuming all parameters are available

$available = true;

$missingparams = "";

foreach($params as $param){

if(!isset($_POST[$param]) || strlen($_POST[$param])<=0){

$available = false;

$missingparams = $missingparams . ", " . $param;

}

//if parameters are missing

if(!$available){

$response = array();

$response['error'] = true;

$response['message'] = 'Parameters ' . substr($missingparams, 1, strlen($missingparams)) . ' missing';

//displaying error

echo json_encode($response);

//stopping further execution

die();

}

//an array to display response

$response = array();

//if it is an api call

//that means a get parameter named api call is set in the URL

//and with this parameter we are concluding that it is an api call

if(isset($_GET['apicall'])){

switch($_GET['apicall']){

//the CREATE operation

//if the api call value is 'createhero'

//we will create a record in the database

case 'createhero':

//first check the parameters required for this request are available or not

isTheseParametersAvailable(array('name','realname','rating','teamaffiliation'));

//creating a new dboperation object

$db = new DbOperation();

//creating a new record in the database

$result = $db->createHero(

$_POST['name'],

$_POST['realname'],

$_POST['rating'],

$_POST['teamaffiliation']

);

//if the record is created adding success to response

if($result){

//record is created means there is no error

$response['error'] = false;

//in message we have a success message

$response['message'] = 'Hero addedd successfully';

//and we are getting all the heroes from the database in the response

$response['heroes'] = $db->getHeroes();

}else{

//if record is not added that means there is an error

$response['error'] = true;

//and we have the error message

$response['message'] = 'Some error occurred please try again';

}

break;

//the READ operation

//if the call is getheroes

case 'getheroes':

$db = new DbOperation();

$response['error'] = false;

$response['message'] = 'Request successfully completed';

$response['heroes'] = $db->getHeroes();

break;

//the UPDATE operation

case 'updatehero':

isTheseParametersAvailable(array('id','name','realname','rating','teamaffiliation'));

$db = new DbOperation();

$result = $db->updateHero(

$_POST['id'],

$_POST['name'],

$_POST['realname'],

$_POST['rating'],

$_POST['teamaffiliation']

);

if($result){

$response['error'] = false;

$response['message'] = 'Hero updated successfully';

$response['heroes'] = $db->getHeroes();

}else{

$response['error'] = true;

$response['message'] = 'Some error occurred please try again';

}

break;

//the delete operation

case 'deletehero':

//for the delete operation we are getting a GET parameter from the url having the id of the record to be deleted

if(isset($_GET['id'])){

$db = new DbOperation();

if($db->deleteHero($_GET['id'])){

$response['error'] = false;

$response['message'] = 'Hero deleted successfully';

$response['heroes'] = $db->getHeroes();

}else{

$response['error'] = true;

$response['message'] = 'Some error occurred please try again';

}

}else{

$response['error'] = true;

$response['message'] = 'Nothing to delete, provide an id please';

}

break;

}

}else{

//if it is not api call

//pushing appropriate values to response array

$response['error'] = true;

$response['message'] = 'Invalid API Call';

}

//displaying the response in json structure

echo json_encode($response);

Now lets test the APIs.

Testing the API Calls

For testing the API Calls here I am using POSTMAN. It is a REST API Client for Google Chrome.

Create Operation

Read Operation

Update Operation

Delete Operation

You see all the operations are working absolutely fine. Now we can move ahead in creating our Android Project. But before moving to android side below you can see our API URLs.

Finalizing API Calls

The below table displays our API URLs with the Parameter and Method. Remember using localhost in android side will not work. You need to find your IP. I have my IP in the below table, but in your case you need to find yours. So if you are using a windows you can use ipconfig command to find IP and for MAC or Linux use the ifconfig command. For more details you can visit this tutorial.

POST: http://192.168.101.1/HeroApi/v1/Api.php?apicall=createhero
GET: http://192.168.101.1/HeroApi/v1/Api.php?apicall=getheroes
POST: http://192.168.101.1/HeroApi/v1/Api.php?apicall=updatehero
GET: http://192.168.101.1/HeroApi/v1/Api.php?apicall=deletehero&id=idvalue

Want to Explore Building RESTful APIs?

Here we built a very basic API that demonstrates the CRUD operation. But in real world scenarios we use FRAMEWORKS to make the API creating easy and structured. If you want to dig a bit more about building RESTful APIs. Then you should check the following course. It is absolutely FREE.

Android MySQL Tutorial

We have our Web Services, and now we can build the android application. So lets start.

Creating a new Project

Create a new Android Studio Project. Here I have created a project named MyHeroApp.
Once your project is loaded inside the package we will create all the helper classes that is required for thie project.

Creating Helper Classes

Class To Store API URLs

First create a class named Api.java and write the following code.

package net.simplifiedlearning.myheroapp;

/**

* Created by Belal on 9/9/2017.

public class Api {

private static final String ROOT_URL = "http://192.168.101.1/HeroApi/v1/Api.php?apicall=";

public static final String URL_CREATE_HERO = ROOT_URL + "createhero";

public static final String URL_READ_HEROES = ROOT_URL + "getheroes";

public static final String URL_UPDATE_HERO = ROOT_URL + "updatehero";

public static final String URL_DELETE_HERO = ROOT_URL + "deletehero&id=";

}

Hero Model Class

We also need a model class for our Hero. So create a class named Hero.java and write the following code. It will have only properties, constructor and getters.

package net.simplifiedlearning.myheroapp;

import java.io.Serializable;

/**

* Created by Belal on 9/9/2017.

class Hero {

private int id;

private String name, realname;

private int rating;

private String teamaffiliation;

public Hero(int id, String name, String realname, int rating, String teamaffiliation) {

this.id = id;

this.name = name;

this.realname = realname;

this.rating = rating;

this.teamaffiliation = teamaffiliation;

}

public int getId() {

return id;

}

public String getName() {

return name;

}

public String getRealname() {

return realname;

}

public int getRating() {

return rating;

}

public String getTeamaffiliation() {

return teamaffiliation;

}

Request Handler

We need to send GET and POST request to our API URLs, and for this I am creating a new class that will perform these tasks. So create a new class named RequestHandler.java and write the following code.

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package net.simplifiedlearning.myheroapp;

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.InputStreamReader;

import java.io.OutputStream;

import java.io.OutputStreamWriter;

import java.io.UnsupportedEncodingException;

import java.net.HttpURLConnection;

import java.net.URL;

import java.net.URLEncoder;

import java.util.HashMap;

import java.util.Map;

import javax.net.ssl.HttpsURLConnection;

/**

* Created by Belal on 9/9/2017.

public class RequestHandler {

//Method to send httpPostRequest

//This method is taking two arguments

//First argument is the URL of the script to which we will send the request

//Other is an HashMap with name value pairs containing the data to be send with the request

public String sendPostRequest(String requestURL,

HashMap<String, String> postDataParams) {

//Creating a URL

URL url;

//StringBuilder object to store the message retrieved from the server

StringBuilder sb = new StringBuilder();

try {

//Initializing Url

url = new URL(requestURL);

//Creating an httmlurl connection

HttpURLConnection conn = (HttpURLConnection) url.openConnection();

//Configuring connection properties

conn.setReadTimeout(15000);

conn.setConnectTimeout(15000);

conn.setRequestMethod("POST");

conn.setDoInput(true);

conn.setDoOutput(true);

//Creating an output stream

OutputStream os = conn.getOutputStream();

//Writing parameters to the request

//We are using a method getPostDataString which is defined below

BufferedWriter writer = new BufferedWriter(

new OutputStreamWriter(os, "UTF-8"));

writer.write(getPostDataString(postDataParams));

writer.flush();

writer.close();

os.close();

int responseCode = conn.getResponseCode();

if (responseCode == HttpsURLConnection.HTTP_OK) {

BufferedReader br = new BufferedReader(new InputStreamReader(conn.getInputStream()));

sb = new StringBuilder();

String response;

//Reading server response

while ((response = br.readLine()) != null) {

sb.append(response);

}

} catch (Exception e) {

e.printStackTrace();

}

return sb.toString();

}

public String sendGetRequest(String requestURL) {

StringBuilder sb = new StringBuilder();

try {

URL url = new URL(requestURL);

HttpURLConnection con = (HttpURLConnection) url.openConnection();

BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(con.getInputStream()));

String s;

while ((s = bufferedReader.readLine()) != null) {

sb.append(s + "\n");

}

} catch (Exception e) {

}

return sb.toString();

}

private String getPostDataString(HashMap<String, String> params) throws UnsupportedEncodingException {

StringBuilder result = new StringBuilder();

boolean first = true;

for (Map.Entry<String, String> entry : params.entrySet()) {

if (first)

first = false;

else

result.append("&");

result.append(URLEncoder.encode(entry.getKey(), "UTF-8"));

result.append("=");

result.append(URLEncoder.encode(entry.getValue(), "UTF-8"));

}

return result.toString();

}

Defining Internet Permission in AndroidManifest

As we need to perform network request from our Application, we need to define internet permission for this. And because we are working with localhost our APIs are not secured i.e. we have HTTP URLs and not HTTPS for our APIs.
And by default your application are restricted to communicate with non HTTPS URLs (For security reasons). So you need to explicitly define that your app should be allowed to communicate with HTTP URLs. And to do this you need to add usesCleartextTraffic=”true” inside your opening application tag. (See the below code that is AndroidManifest.xml for my project.).

<?xml version="1.0" encoding="utf-8"?>

<manifest xmlns:android="http://schemas.android.com/apk/res/android"

package="net.simplifiedlearning.myheroapp">

<uses-permission android:name="android.permission.INTERNET" />

<application

android:usesCleartextTraffic="true"

android:allowBackup="true"

android:icon="@mipmap/ic_launcher"

android:label="@string/app_name"

android:roundIcon="@mipmap/ic_launcher_round"

android:supportsRtl="true"

android:theme="@style/AppTheme">

<intent-filter>

</intent-filter>

</activity>

</application>

</manifest>

Designing User Interface

The below image shows how our final application will look.

So we need to design the above mentioned things. I have already designed the activity_main.xml so you can directly use the below code.

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:layout_width="match_parent"

android:layout_height="match_parent"

tools:context="net.simplifiedlearning.myheroapp.MainActivity">

<LinearLayout

android:id="@+id/linearLayout"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_alignParentTop="true"

android:orientation="vertical"

android:padding="16dp">

<EditText

android:id="@+id/editTextHeroId"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:visibility="gone" />

<EditText

android:id="@+id/editTextName"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_marginBottom="8dp"

android:layout_marginTop="8dp"

android:hint="Name" />

<EditText

android:id="@+id/editTextRealname"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_marginBottom="8dp"

android:layout_marginTop="8dp"

android:hint="Realname" />

<RatingBar

android:id="@+id/ratingBar"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:numStars="5"

android:stepSize="1" />

<Spinner

android:id="@+id/spinnerTeamAffiliation"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_marginBottom="8dp"

android:layout_marginTop="8dp"

android:entries="@array/teams" />

<Button

android:id="@+id/buttonAddUpdate"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:text="Add" />

</LinearLayout>

<ListView

android:id="@+id/listViewHeroes"

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:layout_below="@id/linearLayout" />

<ProgressBar

android:id="@+id/progressBar"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_centerHorizontal="true"

android:layout_centerVertical="true"

android:visibility="gone" />

</RelativeLayout>

For the spinner I have used static entries using xml array. So you also need to create this array. For this go inside values -> strings.xml

<string name="app_name">Android MySQL CRUD</string>

<item>Avengers</item>

<item>Justice League</item>

<item>Fantastic Four</item>

</array>

</resources>

Thats it for the User Interface part.
Now lets perform the CRUD operations in our MySQL database.

Class to Perform Network Request

The point is we cannot directly perform a network request in the application’s main thread. So for this we need an AsyncTask to perform the task in a separate thread. Hence we will create an inner class inside MainActivity.java.

//inner class to perform network request extending an AsyncTask

private class PerformNetworkRequest extends AsyncTask<Void, Void, String> {

//the url where we need to send the request

String url;

//the parameters

HashMap<String, String> params;

//the request code to define whether it is a GET or POST

int requestCode;

//constructor to initialize values

PerformNetworkRequest(String url, HashMap<String, String> params, int requestCode) {

this.url = url;

this.params = params;

this.requestCode = requestCode;

}

//when the task started displaying a progressbar

@Override

protected void onPreExecute() {

super.onPreExecute();

progressBar.setVisibility(View.VISIBLE);

}

//this method will give the response from the request

@Override

protected void onPostExecute(String s) {

super.onPostExecute(s);

progressBar.setVisibility(GONE);

try {

JSONObject object = new JSONObject(s);

if (!object.getBoolean("error")) {

Toast.makeText(getApplicationContext(), object.getString("message"), Toast.LENGTH_SHORT).show();

//refreshing the herolist after every operation

//so we get an updated list

//we will create this method right now it is commented

//because we haven't created it yet

//refreshHeroList(object.getJSONArray("heroes"));

}

} catch (JSONException e) {

e.printStackTrace();

}

//the network operation will be performed in background

@Override

protected String doInBackground(Void... voids) {

RequestHandler requestHandler = new RequestHandler();

if (requestCode == CODE_POST_REQUEST)

return requestHandler.sendPostRequest(url, params);

if (requestCode == CODE_GET_REQUEST)

return requestHandler.sendGetRequest(url);

return null;

}

Create Operation

Now lets save a new hero to our database. First we will define all the views. And we will attach a clicklistener to the button and inside the click event we will call the method to create a new record in the database.

public class MainActivity extends AppCompatActivity {

private static final int CODE_GET_REQUEST = 1024;

private static final int CODE_POST_REQUEST = 1025;

//defining views

EditText editTextHeroId, editTextName, editTextRealname;

RatingBar ratingBar;

Spinner spinnerTeam;

ProgressBar progressBar;

ListView listView;

Button buttonAddUpdate;

//we will use this list to display hero in listview

List<Hero> heroList;

//as the same button is used for create and update

//we need to track whether it is an update or create operation

//for this we have this boolean

boolean isUpdating = false;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

editTextHeroId = (EditText) findViewById(R.id.editTextHeroId);

editTextName = (EditText) findViewById(R.id.editTextName);

editTextRealname = (EditText) findViewById(R.id.editTextRealname);

ratingBar = (RatingBar) findViewById(R.id.ratingBar);

spinnerTeam = (Spinner) findViewById(R.id.spinnerTeamAffiliation);

buttonAddUpdate = (Button) findViewById(R.id.buttonAddUpdate);

progressBar = (ProgressBar) findViewById(R.id.progressBar);

listView = (ListView) findViewById(R.id.listViewHeroes);

heroList = new ArrayList<>();

buttonAddUpdate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

//if it is updating

if (isUpdating) {

//calling the method update hero

//method is commented becuase it is not yet created

//updateHero();

} else {

//if it is not updating

//that means it is creating

//so calling the method create hero

createHero();

}

});

//calling the method read heroes to read existing heros from the database

//method is commented because it is not yet created

//readHeroes();

}

Now we need to create the method createHero().

private void createHero() {

String name = editTextName.getText().toString().trim();

String realname = editTextRealname.getText().toString().trim();

int rating = (int) ratingBar.getRating();

String team = spinnerTeam.getSelectedItem().toString();

//validating the inputs

if (TextUtils.isEmpty(name)) {

editTextName.setError("Please enter name");

editTextName.requestFocus();

return;

}

if (TextUtils.isEmpty(realname)) {

editTextRealname.setError("Please enter real name");

editTextRealname.requestFocus();

return;

}

//if validation passes

HashMap<String, String> params = new HashMap<>();

params.put("name", name);

params.put("realname", realname);

params.put("rating", String.valueOf(rating));

params.put("teamaffiliation", team);

//Calling the create hero API

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_CREATE_HERO, params, CODE_POST_REQUEST);

request.execute();

}

Now run the application and try adding a new hero.

android mysql tutorial - create operation — Android MySQL – Create Operation

Its working fine, you can check the database as well. Now lets move to the read operation.

Read Operation

We will display all the heroes from the database in a ListView, the ListView also have the Update and Delete Button.
So for this first we will create a custom Layout for our ListView.

List Layout

Create a layout resource file named layout_hero_list.xml.

<?xml version="1.0" encoding="utf-8"?>

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:orientation="horizontal"

android:padding="8dp">

<TextView

android:id="@+id/textViewName"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_weight="8"

android:text="Captain America"

android:textAppearance="@style/Base.TextAppearance.AppCompat.Medium" />

<TextView

android:textStyle="bold"

android:id="@+id/textViewUpdate"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBottom="@+id/textViewDelete"

android:layout_toLeftOf="@+id/textViewDelete"

android:layout_toStartOf="@+id/textViewDelete"

android:padding="5dp"

android:text="Update"

android:textColor="#498C1A" />

<TextView

android:textStyle="bold"

android:id="@+id/textViewDelete"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:padding="5dp"

android:text="Delete"

android:textColor="#C20A10" />

</RelativeLayout>

Custom Adapter Class

Create one more inner class inside MainActivity class. We will name it HeroAdapter.

class HeroAdapter extends ArrayAdapter<Hero> {

//our hero list

List<Hero> heroList;

//constructor to get the list

public HeroAdapter(List<Hero> heroList) {

super(MainActivity.this, R.layout.layout_hero_list, heroList);

this.heroList = heroList;

}

//method returning list item

@Override

public View getView(int position, View convertView, ViewGroup parent) {

LayoutInflater inflater = getLayoutInflater();

View listViewItem = inflater.inflate(R.layout.layout_hero_list, null, true);

//getting the textview for displaying name

TextView textViewName = listViewItem.findViewById(R.id.textViewName);

//the update and delete textview

TextView textViewUpdate = listViewItem.findViewById(R.id.textViewUpdate);

TextView textViewDelete = listViewItem.findViewById(R.id.textViewDelete);

final Hero hero = heroList.get(position);

textViewName.setText(hero.getName());

//attaching click listener to update

textViewUpdate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

//so when it is updating we will

//make the isUpdating as true

isUpdating = true;

//we will set the selected hero to the UI elements

editTextHeroId.setText(String.valueOf(hero.getId()));

editTextName.setText(hero.getName());

editTextRealname.setText(hero.getRealname());

ratingBar.setRating(hero.getRating());

spinnerTeam.setSelection(((ArrayAdapter<String>) spinnerTeam.getAdapter()).getPosition(hero.getTeamaffiliation()));

//we will also make the button text to Update

buttonAddUpdate.setText("Update");

}

});

//when the user selected delete

textViewDelete.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

// we will display a confirmation dialog before deleting

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);

builder.setTitle("Delete " + hero.getName())

.setMessage("Are you sure you want to delete it?")

.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

//if the choice is yes we will delete the hero

//method is commented because it is not yet created

//deleteHero(hero.getId());

}

})

.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

}

})

.setIcon(android.R.drawable.ic_dialog_alert)

.show();

}

});

return listViewItem;

}

Retrieving Heroes from the Database

Create a method named readHeroes().

private void readHeroes() {

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_READ_HEROES, null, CODE_GET_REQUEST);

request.execute();

}

Now one more method we need to refresh the Hero List. So create a method named refreshHeroList().

private void refreshHeroList(JSONArray heroes) throws JSONException {

//clearing previous heroes

heroList.clear();

//traversing through all the items in the json array

//the json we got from the response

for (int i = 0; i < heroes.length(); i++) {

//getting each hero object

JSONObject obj = heroes.getJSONObject(i);

//adding the hero to the list

heroList.add(new Hero(

obj.getInt("id"),

obj.getString("name"),

obj.getString("realname"),

obj.getInt("rating"),

obj.getString("teamaffiliation")

));

}

//creating the adapter and setting it to the listview

HeroAdapter adapter = new HeroAdapter(heroList);

listView.setAdapter(adapter);

}

Now also uncomment the commented method inside PeformNetworkRequest class and onCreate() method. You need to uncomment readHeroes() inside onCreate() and refreshHeroList() inside PerformNetworkRequest class.
Now you can try running the application.

android mysql tutorial - read operation — Android MySQL – Read Operation

You can see it is also working fine. Now lets do the UPDATE operation.

Update Operation

For updating we will create a new method named updateHero().

private void updateHero() {

String id = editTextHeroId.getText().toString();

String name = editTextName.getText().toString().trim();

String realname = editTextRealname.getText().toString().trim();

int rating = (int) ratingBar.getRating();

String team = spinnerTeam.getSelectedItem().toString();

if (TextUtils.isEmpty(name)) {

editTextName.setError("Please enter name");

editTextName.requestFocus();

return;

}

if (TextUtils.isEmpty(realname)) {

editTextRealname.setError("Please enter real name");

editTextRealname.requestFocus();

return;

}

HashMap<String, String> params = new HashMap<>();

params.put("id", id);

params.put("name", name);

params.put("realname", realname);

params.put("rating", String.valueOf(rating));

params.put("teamaffiliation", team);

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_UPDATE_HERO, params, CODE_POST_REQUEST);

request.execute();

buttonAddUpdate.setText("Add");

editTextName.setText("");

editTextRealname.setText("");

ratingBar.setRating(0);

spinnerTeam.setSelection(0);

isUpdating = false;

}

Now just uncomment the method updateHero() inside the click listener of buttonAddUpdate.
And now we can try updating a record.

android mysql tutorial - update operation — Android MySQL – Update Operation

So the update is also working absolutely fine. Now lets move to the last operation which is delete.

Delete Operation

For delete also we need a new method. So create a method named deleteHero().

private void deleteHero(int id) {

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_DELETE_HERO + id, null, CODE_GET_REQUEST);

request.execute();

}

Now uncomment the method deleteHero() inside the HeroAdapter class.
And lets test the delete operation as well.

android mysql tutorial - delete operation — Android MySQL – Delete Operation

So it is working fine as well. And we have done with all the basic CRUD operations.

The complete code for MainActivity

If you had some confusions following the above steps here is the complete code for MainActivity.java.

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package net.simplifiedlearning.myheroapp;

import android.content.DialogInterface;

import android.os.AsyncTask;

import android.os.Bundle;

import android.support.v7.app.AlertDialog;

import android.support.v7.app.AppCompatActivity;

import android.text.TextUtils;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.ArrayAdapter;

import android.widget.Button;

import android.widget.EditText;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.RatingBar;

import android.widget.Spinner;

import android.widget.TextView;

import android.widget.Toast;

import org.json.JSONArray;

import org.json.JSONException;

import org.json.JSONObject;

import java.util.ArrayList;

import java.util.HashMap;

import java.util.List;

import static android.view.View.GONE;

public class MainActivity extends AppCompatActivity {

private static final int CODE_GET_REQUEST = 1024;

private static final int CODE_POST_REQUEST = 1025;

EditText editTextHeroId, editTextName, editTextRealname;

RatingBar ratingBar;

Spinner spinnerTeam;

ProgressBar progressBar;

ListView listView;

Button buttonAddUpdate;

List<Hero> heroList;

boolean isUpdating = false;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

editTextHeroId = (EditText) findViewById(R.id.editTextHeroId);

editTextName = (EditText) findViewById(R.id.editTextName);

editTextRealname = (EditText) findViewById(R.id.editTextRealname);

ratingBar = (RatingBar) findViewById(R.id.ratingBar);

spinnerTeam = (Spinner) findViewById(R.id.spinnerTeamAffiliation);

buttonAddUpdate = (Button) findViewById(R.id.buttonAddUpdate);

progressBar = (ProgressBar) findViewById(R.id.progressBar);

listView = (ListView) findViewById(R.id.listViewHeroes);

heroList = new ArrayList<>();

buttonAddUpdate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

if (isUpdating) {

updateHero();

} else {

createHero();

}

});

readHeroes();

}

private void createHero() {

String name = editTextName.getText().toString().trim();

String realname = editTextRealname.getText().toString().trim();

int rating = (int) ratingBar.getRating();

String team = spinnerTeam.getSelectedItem().toString();

if (TextUtils.isEmpty(name)) {

editTextName.setError("Please enter name");

editTextName.requestFocus();

return;

}

if (TextUtils.isEmpty(realname)) {

editTextRealname.setError("Please enter real name");

editTextRealname.requestFocus();

return;

}

HashMap<String, String> params = new HashMap<>();

params.put("name", name);

params.put("realname", realname);

params.put("rating", String.valueOf(rating));

params.put("teamaffiliation", team);

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_CREATE_HERO, params, CODE_POST_REQUEST);

request.execute();

}

private void readHeroes() {

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_READ_HEROES, null, CODE_GET_REQUEST);

request.execute();

}

private void updateHero() {

String id = editTextHeroId.getText().toString();

String name = editTextName.getText().toString().trim();

String realname = editTextRealname.getText().toString().trim();

int rating = (int) ratingBar.getRating();

String team = spinnerTeam.getSelectedItem().toString();

if (TextUtils.isEmpty(name)) {

editTextName.setError("Please enter name");

editTextName.requestFocus();

return;

}

if (TextUtils.isEmpty(realname)) {

editTextRealname.setError("Please enter real name");

editTextRealname.requestFocus();

return;

}

HashMap<String, String> params = new HashMap<>();

params.put("id", id);

params.put("name", name);

params.put("realname", realname);

params.put("rating", String.valueOf(rating));

params.put("teamaffiliation", team);

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_UPDATE_HERO, params, CODE_POST_REQUEST);

request.execute();

buttonAddUpdate.setText("Add");

editTextName.setText("");

editTextRealname.setText("");

ratingBar.setRating(0);

spinnerTeam.setSelection(0);

isUpdating = false;

}

private void deleteHero(int id) {

PerformNetworkRequest request = new PerformNetworkRequest(Api.URL_DELETE_HERO + id, null, CODE_GET_REQUEST);

request.execute();

}

private void refreshHeroList(JSONArray heroes) throws JSONException {

heroList.clear();

for (int i = 0; i < heroes.length(); i++) {

JSONObject obj = heroes.getJSONObject(i);

heroList.add(new Hero(

obj.getInt("id"),

obj.getString("name"),

obj.getString("realname"),

obj.getInt("rating"),

obj.getString("teamaffiliation")

));

}

HeroAdapter adapter = new HeroAdapter(heroList);

listView.setAdapter(adapter);

}

private class PerformNetworkRequest extends AsyncTask<Void, Void, String> {

String url;

HashMap<String, String> params;

int requestCode;

PerformNetworkRequest(String url, HashMap<String, String> params, int requestCode) {

this.url = url;

this.params = params;

this.requestCode = requestCode;

}

@Override

protected void onPreExecute() {

super.onPreExecute();

progressBar.setVisibility(View.VISIBLE);

}

@Override

protected void onPostExecute(String s) {

super.onPostExecute(s);

progressBar.setVisibility(GONE);

try {

JSONObject object = new JSONObject(s);

if (!object.getBoolean("error")) {

Toast.makeText(getApplicationContext(), object.getString("message"), Toast.LENGTH_SHORT).show();

refreshHeroList(object.getJSONArray("heroes"));

}

} catch (JSONException e) {

e.printStackTrace();

}

@Override

protected String doInBackground(Void... voids) {

RequestHandler requestHandler = new RequestHandler();

if (requestCode == CODE_POST_REQUEST)

return requestHandler.sendPostRequest(url, params);

if (requestCode == CODE_GET_REQUEST)

return requestHandler.sendGetRequest(url);

return null;

}

class HeroAdapter extends ArrayAdapter<Hero> {

List<Hero> heroList;

public HeroAdapter(List<Hero> heroList) {

super(MainActivity.this, R.layout.layout_hero_list, heroList);

this.heroList = heroList;

}

@Override

public View getView(int position, View convertView, ViewGroup parent) {

LayoutInflater inflater = getLayoutInflater();

View listViewItem = inflater.inflate(R.layout.layout_hero_list, null, true);

TextView textViewName = listViewItem.findViewById(R.id.textViewName);

TextView textViewUpdate = listViewItem.findViewById(R.id.textViewUpdate);

TextView textViewDelete = listViewItem.findViewById(R.id.textViewDelete);

final Hero hero = heroList.get(position);

textViewName.setText(hero.getName());

textViewUpdate.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

isUpdating = true;

editTextHeroId.setText(String.valueOf(hero.getId()));

editTextName.setText(hero.getName());

editTextRealname.setText(hero.getRealname());

ratingBar.setRating(hero.getRating());

spinnerTeam.setSelection(((ArrayAdapter<String>) spinnerTeam.getAdapter()).getPosition(hero.getTeamaffiliation()));

buttonAddUpdate.setText("Update");

}

});

textViewDelete.setOnClickListener(new View.OnClickListener() {

@Override

public void onClick(View view) {

AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);

builder.setTitle("Delete " + hero.getName())

.setMessage("Are you sure you want to delete it?")

.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

deleteHero(hero.getId());

}

})

.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {

public void onClick(DialogInterface dialog, int which) {

}

})

.setIcon(android.R.drawable.ic_dialog_alert)

.show();

}

});

return listViewItem;

}

So after following every step correctly your application will behave as shown below.

Android MySQL Tutorial – Source Code Download

If you are still facing troubles you can get my source code from below. It has everything, the server side scripts, database file and android project.

Android MySQL Tutorial Source Code

So thats all for this Android MySQL Tutorial friends. CRUD Operation is needed in almost every application so it is a very important thing. If you are having any confusions or queries regarding this Android MySQL tutorial don’t hesitate in asking on comments. And if you liked the post then PLEASE SHARE IT. Thank You 🙂

Belal Khan

Hi, my name is Belal Khan and I am a Google Developers Expert (GDE) for Android. The passion of teaching made me create this blog. If you are an Android Developer, or you are learning about Android Development, then I can help you a lot with Simplified Coding.

Checkout these tutorials as well:

109 thoughts on “Android MySQL Tutorial to Perform Basic CRUD Operation”

LEE CHEE PHANG
October 28, 2015 at 8:30 am
This is great ! Thanks author, i really like your post so much and it is up to date… Thumbs UP !
Reply
PRATHAP
October 28, 2015 at 12:51 pm
Just blowed away bro..!! just trying for almost two days…bt you made it so simple…10 minutes job…bt it took more than a days count bt failed even…thankx bro…cheers (y)
Reply
Kowa
October 29, 2015 at 8:32 am
Awesome tutorial !! Thank you Belal !!
Reply
Kevien
October 29, 2015 at 8:34 am
Thanks a lot.great one!!really easy to understand for beginner.
Reply
Renan Marcos da Silva
April 8, 2016 at 12:41 am
AMAZING BRO! Thank you so much, you really help me!
Reply
laxmi
June 23, 2016 at 6:56 am
Hi Mr.Belal ,this is very much helpful ,thank you so much for this awesome tutorial.
Reply
reza
June 24, 2016 at 3:00 pm
hi , its so helping me!,
all code above, work so well, thank you
cheers!
Reply
Amit
September 5, 2016 at 5:29 am
Awesome Stuff a big help!!!
Reply
Ahmad Atho' Miftahuddin
November 21, 2016 at 2:33 pm
Thank You very much, this is working
Reply
Jack77
December 7, 2016 at 1:43 am
Just want to say you rock man!
Thank you very much for this tutorial, other tutorial use some depecrated class, but this one is up-to-date!
Reply
Ashish
December 21, 2016 at 8:07 am
Amazing !!! great job… Never failed to surprise me for running program without error. Keep it up . Best Tut…
Reply
Vino
December 28, 2016 at 6:29 am
Thank you so much ! Helped a lot !
Reply
BENDEK
May 14, 2017 at 1:14 am
GREAT TUTORIAL, VERY USEFUL…THANKS
Reply
wan
August 26, 2017 at 6:30 pm
Hi Belal,
Thanks for the tutorial.
the tutorial very easy to understands.Thanks man
Reply
Romahdon Akbar Sholeh
September 12, 2017 at 2:19 am
woow Thanks Brother Amazing …..
Reply
vikas yadav
September 14, 2017 at 8:41 am
can’t connect to mysql and inesrt to data
so please help me
Reply
- Sagar Mahewar
  September 16, 2017 at 2:19 pm
  Hello VikasYadav, what error its showing, can you share details ?
  Reply
Elise Marchis
September 16, 2017 at 12:43 am
I have tried many times, but always the error in the layout / activity_main.xml file in the block below:

ERROR RETURN:
Error: (52, 30) No resource found that matches the given name (at ‘entries’ with value ‘@ array / teams’).
Can anyone help?
WIN7 / 64 / ANDROID STUDIO ver 2.3.3
thanks
Reply
- Belal Khan
  September 17, 2017 at 3:06 am
  You just forget to create the array that we are using for the spinner items. Please check the Designing User Interface Part carefully.
  Reply
  - Elise Marchis
    September 19, 2017 at 9:41 pm
    Thanks. Works!! Great post. It helped a lot.
    Reply
Siegfried
September 18, 2017 at 7:11 pm
Great turorial!
I’m using this example for creating my own project.
Only i’m using Volley.
The problem is that i get an ‘Invalid API call’ error message.
How do i pass the ‘apicall’ to the php-file? Map getParams?
Thanks
Reply
- yassine chilali
  October 8, 2018 at 2:24 pm
  public class Api {
  private static final String ROOT_URL = “http://192.168.101.1/HeroApi/v1/Api.php?apicall=”;
  Reply
umi
September 19, 2017 at 5:48 am
can you give the coding how to view in another page not the same page.
Reply
- Belal Khan
  September 19, 2017 at 5:51 am
  The process is same.. Where you are stuck? You can check this youtube playlist https://goo.gl/oqY7Bi
  This may help you
  Reply
  - randy falendo
    November 15, 2018 at 2:28 pm
    please help me sir, i am confuse at “Class to Perform Network Request” , “Create Operation” and create the method createHero().
    how to input that script??? input in a same at mainactivity.java ? if true, i always failed
    Reply
Indrawan Faisal
September 21, 2017 at 12:50 pm
hello mr belal, thank you for your tutorial, i really appreciate it, this tutorial is rally easy to understand, but i have some question, i’m learning your code and because of my laziness i only make 2 attribute on my sql table, just id and name, every operation is working fine, but when im insert data and try to update there’s some error, it says
Warning: mysqli_stmt::bind_param(): Number of elements in type definition string doesn’t match number of bind variables in /home/faisal/Public/Web/android_sql_api/includes/DbOperation.php on line 24
And Heres Line 24 on my DbOperation File
21. //Create operation
22. function insertData($name) {
23. $stmt = $this->con->prepare(“INSERT INTO myTable (name) VALUES (?)”);
24. $stmt->bind_param(“ssis”, $name);
25. if($stmt->execute())
26. return true;
27. return false;
28. }
And This is My Insert Case on main php
case ‘insertData’:
//first check the parameters required for this request are available or not
availableParameters(array(‘name’));
//create a new operation object
$db = new DbOperation();
//create a record by call insert method
$result = $db->insertData(
$_POST[‘name’]
);
//if the record is created adding success to response
if($result) {
//record is created means no error
$response[‘error’] = false;
//in message we have a success message
$response[‘message’] = ‘Record added successfully’;
//reload the data
$response[‘data’] = $db->getData();
} else {
//if record is not added that means there is an error
$response[‘error’] = true;
//and we have error message
$response[‘message’] = ‘some error occurred, please try again’;
}
break;
i’m on the test step and using Postman chrome app as you recommended, thank you, i really appreciate if you want to help
sorry for english
Reply
- Belal Khan
  September 22, 2017 at 3:51 am
  In this line
  $stmt->bind_param(“ssis”, $name);
  you are using only a single string to bind so it should be
  $stmt->bind_param(“s”, $name);
  Reply
  - Indrawan Faisal
    September 23, 2017 at 5:15 am
    oh, thank you very much, in that case i’ll begin to learn for more, god bless you mr belal
    Reply
jordan
September 24, 2017 at 5:11 pm
how to use test this online mysql database. not getting any response from the dbconnect file
Reply
jordan
September 26, 2017 at 10:42 pm
hello bilal,
I have issues with the PhP scripts ,the DbConnect.php Is returning an empty page without any message
Regards
Reply
Napster
September 29, 2017 at 7:49 pm
i get this error when i try to run the app
Error:(98, 70) Gradle: error: URL_CREATE_HERO has private access in Api
Error:(103, 70) Gradle: error: URL_READ_HEROES has private access in Api
Error:(137, 70) Gradle: error: URL_UPDATE_HERO has private access in Api
Error:(151, 70) Gradle: error: URL_DELETE_HERO has private access in Api
Please help
Reply
- Belal Khan
  September 30, 2017 at 4:54 am
  Make these constants public by adding public keyword on each line..
  Reply
Joleth Catama
October 13, 2017 at 11:30 pm
Sir Belal, my add form is consist of 2 activities, how will I add it in the database if fields are divided in to two activities.
If I had a chance to show you the activity, to make it clear.
Reply
Joleth Catama
October 13, 2017 at 11:31 pm
Warning: mysqli_stmt::bind_param(): Number of elements in type definition string doesn’t match number of bind variables in
C:\xampp\htdocs\www\includes\dboperations.php on line
28
{“error”:true,”message”:”Some error occurred please try again”}
Can you help me?
Reply
- Joleth Catama
  October 13, 2017 at 11:45 pm
  oh, no need. thanks.
  Reply
Joleth Catama
October 16, 2017 at 3:50 pm
I copied everything here, to have a sample app. But it doesn’t work. :3
Reply
diego
October 20, 2017 at 2:57 pm
Hi, i have a problem when i put the url on POST MAN showing this problem:
“error”: true,
“message”: “Parameters name, realname, rating, teamaffiliation missing”
what could it means? i nwe in android, please helpppp D:
Reply
- Belal Khan
  October 22, 2017 at 7:28 am
  Please check the video that I embedded in this post. 🙂
  Reply
Nishan
October 30, 2017 at 5:54 am
I have a problem
error:
JSONException: Value Connection of type java.lang.String cannot be converted to JSONObject
Reply
vishal
November 9, 2017 at 11:14 am
Hello sir,This is really great tutorial.
I want to insert table data in thai language and retrive it in same.
i am able to insert data in thai language but unable to get response in thai.
any solution??
Reply
asn
November 17, 2017 at 6:48 am
AoA, hi i have Coppied every thing in a sample project, but i am getting
{“error”:true,”message”:”Invalid API Call”}
this when i run API.php
kindly tell me what is this where is API calling.
P.S em newbie to PHP and andriod.
help would be appriciated thanks
Reply
- Belal Khan
  November 17, 2017 at 10:00 am
  Check the video embedded in this post as well.
  Reply
jamsheer
November 21, 2017 at 4:11 pm
{“error”:true,”message”:”Parameters name, realname, rating, teamaffiliation missing”}
What is this error ?? I’m getting the above error while testing api with postman
Reply
- Belal Khan
  November 22, 2017 at 1:36 pm
  You have to send the parameters with the request as well, check the video that I embedded with this post.
  Reply
Damiano
December 10, 2017 at 7:38 pm
Very good tutorial!
If i’m running the server on linux (Raspberry) where do I put the api folder? I’m using LAMP. Thanks
Reply
Sadiq
December 19, 2017 at 8:59 pm
when testing the api on postman, errors occurred pls why
Warning: mysqli::__construct(): (HY000/1049): Unknown database ‘android’ in
C:\xampp\htdocs\HeroApi\includes\DbConnect.php on line
27
Failed to connect to MySQL: Unknown database ‘android’
Warning: mysqli::prepare(): Couldn’t fetch mysqli in
C:\xampp\htdocs\HeroApi\includes\DbOperation.php on line
27
Fatal error: Uncaught Error: Call to a member function bind_param() on null in C:\xampp\htdocs\HeroApi\includes\DbOperation.php:28
Stack trace:
#0 C:\xampp\htdocs\HeroApi\v1\Api.php(59): DbOperation->createHero(‘Spiderman’, ‘Peter Parker’, ‘4’, ‘Fantastic Four’)
#1 {main}
thrown in
C:\xampp\htdocs\HeroApi\includes\DbOperation.php on line
28
Reply
- Belal Khan
  December 22, 2017 at 2:16 pm
  The error is pretty self-explaining. Did you create the database named android in phpmyadmin which you are trying to connect?
  Reply
Pranay Anand
December 20, 2017 at 1:30 pm
Can I use retrofit with this?
Reply
- Belal Khan
  December 22, 2017 at 2:14 pm
  Yes obviously I have published a tutorial for this too check it here
  https://www.simplifiedcoding.net/retrofit-android-tutorial/
  Reply
Jairus San Juan
December 23, 2017 at 12:51 pm
Warning: mysqli::__construct(): (HY000/2002): No connection could be made because the target machine actively refused it.
in
C:\xampp\htdocs\HeroApi\includes\DbConnect.php on line
27
Failed to connect to MySQL: No connection could be made because the target machine actively refused it.
Warning: mysqli::prepare(): Couldn’t fetch mysqli in
C:\xampp\htdocs\HeroApi\includes\DbOperation.php on line
27
Fatal error: Uncaught Error: Call to a member function bind_param() on null in C:\xampp\htdocs\HeroApi\includes\DbOperation.php:28
Stack trace:
#0 C:\xampp\htdocs\HeroApi\v1\Api.php(59): DbOperation->createHero(‘wolverine’, ‘Logan’, ‘5’, ‘Justice League’)
#1 {main}
thrown in
C:\xampp\htdocs\HeroApi\includes\DbOperation.php on line
28
this is my error sir, already subscribed at your youtube channel sir, please help. thankyou.
Reply
- Belal Khan
  December 24, 2017 at 7:26 am
  Turn on your MySQL database and Go to browser type localhost/phpmyadmin and see if it is opening or not.
  Reply
sheharyar
December 31, 2017 at 11:14 am
hi bilal thank you for this tutorials. dear bilal i got some issues :
java.net.SocketTimeoutException: failed to connect to /192.168.0.108 (port 80) after 15000ms
please help me out thanks in advance
Reply
Rahmat
December 31, 2017 at 3:14 pm
‘W/System.err: org.json.JSONException: End of input at character 0’ of coming in when running the app
Reply
- martin
  August 3, 2018 at 11:36 pm
  I Have the same problem 🙁
  Reply
Sohel
January 1, 2018 at 11:34 am
Everything is fine, no error looking to my app. but from emulator I cant create Heros, and not showing the heroes list in the list view and also not posting data to my database
Reply
Michael Satterfield
January 5, 2018 at 10:03 am
Wow I found you tutorial to be very simple an step-by-step. Good job. How ever I suffer from a developmental brain damage and am disabled where even simple thing scan be very confusing to work out in practical applications. I I were you give you some money could you help me to build a fairly simple crud reader app for my website which is also for the disabled and home bound. Thank you so very much for you efforts here.
Reply
- Belal Khan
  January 5, 2018 at 10:43 am
  Contact me at probelalkhan@gmail.com
  Reply
hawkin
January 17, 2018 at 4:20 am
hi bilal thank you for this tutorials. u inspire me to learn more android program.
can i add edittext “Textwatcher” to this program ? what should i do to implement the code to make edittext “Textwatcher”. thanks in advance
Reply
hawkin
January 17, 2018 at 4:27 am
edittext “Textwatcher” to filter from the listview
Reply
mayuri
January 22, 2018 at 6:12 am
How do I create an ADMIN PANEL, When ever admin does those actions, all users must get a notification may be a text message, or email or simple push up notification. in android studio
Reply
Silvio Rodrigues Bonilha
February 4, 2018 at 7:53 am
Hello…..great tutorial…. but Add and update doesnt work for me… some problem in POST metod…can you helpme?
Reply
Dominik
February 25, 2018 at 6:20 pm
Hey, great guide, I just have a question. I would like to store the data downloaded from database somewhere inside the application as a variable so I could use it later.
I tried to read the code and also debug to see which variable is used to get data from server (php) to the actual layouts but I couldn’t find that and I have no idea where to look at. Any advice? 🙂
Reply
Andrea Trevi
March 5, 2018 at 6:34 pm
Hi Belal, thank you very much for your hard work whit all tutorials. I’ve have a question about the search operation. I have updated api.php and dboperations.php by adding a search function in order to select the heroes by ID. How can I implement a search field in the android application in order to display the herodisplay them in editable text fields?
Can you please help me in order to undestand how to?
Thanks you!
Regards
Reply
Dejene
March 6, 2018 at 7:03 am
Great work. Well done. I want to add searchHero() method to display a single record where id is provided.
here is my code
// DbOperation.php
function searchHero($id){
$stmt = $this->con->prepare(“SELECT * FROM heros where id=?”);
$stmt->bind_param(“fk_s”, $id);
if($stmt->execute())
return true;
return false;
}
//Api.php
case ‘searchHero’:
$db = new DbOperation();
$result = $db->searchMedicineDetailsAmharic($_POST[‘id’]);
if($result){
$response[‘error’] = false;
$response[‘message’] = ‘Medicine Searched successfully’;
$response[‘medicines’] = $db->getHero();
}else{
$response[‘error’] = true;
$response[‘message’] = ‘Some error occurred please try again’;
}
break;
But when I call the funtion, it does not retrieve the result
{“error”:true,”message”:”Some error occurred please try again”}
Please help.
Reply
- Vinay Shirashyad
  February 26, 2019 at 6:07 am
  Did you get the solution for this problem ?
  Reply
S.M. Bakhtiar
April 9, 2018 at 2:54 am
Excellent Tutorial.It works well.
I have question How do add search option when i add record.
Reply
Rafael dos Anjos
June 1, 2018 at 4:33 am
Super Tutorial Belal Khan, even though I was looking for a tutorial that would work without using volley, retrofit or apache.
Thank you so much.
Are there any examples with dowload and image upload without the use of libraries?
What is the advantage of using third-party libraries?
I’m new to the programming world, especially android, sorry if the question was stupid.
I wait, and thank you again.
(Used by Google Translate)
Reply
Amadou Mamane Nana Fassouma
July 16, 2018 at 5:46 pm
Hello thank you very much for this great tutorial
When i test with an emulator it works very well but if i connect my android it does’nt work, please help me
Reply
Tilak Sharma
July 29, 2018 at 9:33 am
Please tell about CRUD operations with images and text in Mysql PHP ANDROID recycler view
Reply
Ari Martana
August 12, 2018 at 4:40 am
Thanks this works fine for me
Reply
Yaman M Nur
September 15, 2018 at 1:57 am
thanks for tutorial :), this is help me
Reply
Phil Webster
September 21, 2018 at 10:59 am
Very useful tutorial.
It explains why everything is being done, rather than just presenting a bunch of code!
I shall let you know how my App comes along!
Reply
Ateeque Shaikh
November 16, 2018 at 6:04 am
Hi bilal.. Above code not working in my case when I connected my real device with USB and trying to get expected output but not showing anything after clicking on Add button.. Looking forward your positive response..
Reply
Hamdeen
December 28, 2018 at 3:57 pm
Amazing Tutorial and Great Writing . Well Done Belal Thanks
Reply
Bamidele Clement
December 31, 2018 at 11:10 am
Thank you very much for this tutorial. You saved my time!
Reply
Riflan Ahmed
January 8, 2019 at 5:23 pm
Thanks a lot,
The code working fine
The only problem is all the function in the same page
Reply
- Belal Khan
  February 22, 2019 at 12:22 pm
  Organize the code according to your need. I tried to explain in the shortest way possible.
  Reply
Golden
January 31, 2019 at 7:34 pm
Thank You Very Much for this tutourial, Thumbs Up and keep it up, We strongly follow your tuts….
Just one question, how can I modify such code to save the data of these heroes for offline viewing (My Aim is to have an app that synchs MySQL and SQLite Database in both directions) like what Microsoft ToDo App does.
Can You Help me
Reply
mina amir
February 6, 2019 at 8:14 am
you are awesome man , very very professional ..
Reply
Ishak
February 15, 2019 at 4:21 pm
Thank you Bilel i really appreciate this completed project
Reply
Mateoooo
March 10, 2019 at 1:01 pm
Thank you! It’s very clear for understanding. But this method is working for API 27. For API 28 I have some error with connection with database. Could you help me? I can give you more info about my problem.
Reply
Raven
March 14, 2019 at 12:53 pm
How to pass multiple parameters in the url? I want to send parameters not just id. How to do that? Thanks
Reply
Ali
April 24, 2019 at 3:47 pm
Thank you for your work. Does this code work on a remote database (not on the local network) ???
Reply
- Belal Khan
  May 12, 2019 at 11:23 am
  Yes obviously it will work. I also have an updated complete course
  Check this course to learn everything about rest api, mysql and android
  https://www.youtube.com/playlist?list=PLk7v1Z2rk4hhGfJw-IQCm6kjywmuJX4Rh
  In this course you will learn deploying your api to a live host as well.
  Reply
Julius
May 2, 2019 at 10:27 am
Hi..thank you for this tut. It has really helped me.
Though mine is a quick one. I have tested the endpoints with postman and they are all well.
Create is working perfectly on android.
The Problem is am not able to perform a GET request from server to the listview. on postman get request is working perfectly . WHille on my device it’s not.
I have gone the extra mile of downloading the source code but it’s not populating the listview. Could the problem be with my phone or what?
Reply
julius
May 2, 2019 at 9:05 pm
Hi thank you for the tutorial. It really helped me.
Though am having this issue of postman is working perfectly with CRUD service, and am able to create(POST) from android studio.
The funny thing is the data list is not populating on my device even with the source code.
What might be wrong?
Reply
Allan Paulo Daluz
May 28, 2019 at 12:16 pm
Question, Can I use this approach if my database is uploaded in a web server? If yes then how? Should I just change the base url to the url of the web server where my database and .php files are located? Thanks.
Reply
- Belal Khan
  May 31, 2019 at 4:49 am
  Yes ofcourse, that is what we do indeed.
  Reply
julius
June 13, 2019 at 9:50 pm
what if i’d like to select a single record or a user profile how can I go about it?
Reply
Mehdi
July 13, 2019 at 3:31 pm
Awesome!
Very precise and step by step guide. Even those with a limited knowledge of android application can create this app.
Reply
Junel
February 6, 2020 at 1:15 am
thank you very much Belal for this very accurate tutorial.
One thing I will add, in case the app is not working or it is loading for a long time, is make an inbound rule on the Windows firewall Advanced Settings for httpd.exe (in my case the location of the executable is , which is the actual Apache server in case you are accessing from local area network. Also on the Advanced tab check Private under Profiles to be able to access the web server over the LAN from this Android example.
Again, thank you.
Reply
Lucian
February 12, 2020 at 11:14 am
Great TuTS
I want to add a textchangedlistener to a textview so i can search through the listview if the list becomes long.
can you help?
Reply
priyanka
February 18, 2020 at 12:09 pm
when am clicking to add button thier is no event occured so how can i solve this error to perfrom the Add button
Reply
- Belal Khan
  March 14, 2020 at 3:37 am
  Try downloading my source code.
  Reply
KiyarashHeidari
March 17, 2020 at 9:50 am
Thanks.
Reply
kyomaaa
March 31, 2020 at 7:56 am
Good day sir, i have this error while creating a hero
error: cannot find symbol
RequestHandler requestHandler = new RequestHandler();
i badly need your help sir, Thanks!
Reply
Aage Berntsen
June 20, 2020 at 12:12 am
I need help!
My API does not work! It used to work very good, but one day all of my API”s gave me errormessage.
Is there somebody who can help me?
This is the error that i get, and again… it used to work…
{“error”:true,”message”:”Invalid API Call”}
Reply
- Aage Berntsen
  July 15, 2020 at 2:38 pm
  Could it have something with the PHP-version?
  Reply
Henry Ashilonu
October 14, 2020 at 8:27 am
Belal you are really doing great work, I like your passion to make things very clear.
Reply
- Belal Khan
  November 16, 2020 at 5:21 am
  Thank You Friend
  Reply
ryan p
February 12, 2021 at 11:53 pm
So what is the difference between this and a REST API?
Reply
Amaury Almeida Junior
March 12, 2021 at 6:56 pm
I was struggling to find a good article about CRUD with Android, PHP, MySQL. This article is so far the best article ever, not only about the clean and good understanding information, but you can see all kindness that the author had to show to us in detail all the process with good comments inside the code, workflows, etc. But most important, all working 100 % fine! We know do documentation to explain software development is not easy not at all, you need to test and test many times before publishing your thoughts. I saw many articles where you can clearly see that the author just put over the code and when you going to run you see a lot of crashes and bugs, sometimes it’s good to learn how to fix those bugs but sometimes you need good and useful information to learn fast as possible and do your improvement by yourself after.
There are few who have the gift and the patience to teach their knowledge in the best way. Congratulations Belal Khan, I will continue to learn a lot about development with you. I hope you continue your wonderful work helping thousands of people like me. Long life. May the force be with you!
Reply
pratik gaikwad
March 25, 2021 at 6:57 am
this example is helpful for me but i want unable to do with recyclerview not listview
Reply
Ialwayslikelearning
March 25, 2021 at 3:51 pm
Good Evening, I tried practicing with your code, and everything works, until creating data via the android app, after that although the data is being show in MYSQL, it does not update itself in the app list itself for update and delete operation, the layout_hero_list to be exact, I believed that there might be some mistake in my end, hence I tried downloading your original source code and ran via Android Studio and same issue. Please Help, Thank you for the tutorial.
Reply
Shoaib
April 21, 2021 at 7:01 pm
As,salamualikum Belal Bhai,
can is use mySQL for uploading data through app like buy and sell products and also to save login and registration info in the database.
Thanks in advance…
Reply
Sriram
April 1, 2022 at 2:08 pm
This is not working in PHP8.1 while it works ok in 5.5
It was so far has helped with my requirement, but now the PHP version got updated by the service provider. It is not functioning.
Is there another Code you have published for PHP 8.1?
Reply
John Cruz
June 11, 2022 at 6:44 am
Hi Belal,Can someone help me how to get the sourcecode, because my request hasnt been approve yet, thank you. i have already subscribed to your channel
Reply
Francis
June 11, 2022 at 8:24 am
I have this error.
android:exported needs to be explicitly specified for element . Apps targeting Android 12 and higher are required to specify an explicit value for android:exported when the corresponding component has an intent filter defined
Reply
SK
January 2, 2023 at 2:15 pm
Great work. Going thru all your steps to test it. Could you send me the source code?
Reply

What is CRUD?

Why PHP and MySQL and Why Not SQLite?

Do we have only PHP and MySQL for this?

Building Web APIs

Creating Database

Creating PHP Project

Project Structure

Defining Constants

Connecting to Database

Performing Database Operations

Handling API Calls

Testing the API Calls

Create Operation

Read Operation

Update Operation

Delete Operation

Finalizing API Calls

Want to Explore Building RESTful APIs?

Android MySQL Tutorial

Creating a new Project

Creating Helper Classes

Class To Store API URLs

Hero Model Class

Request Handler

Defining Internet Permission in AndroidManifest

Designing User Interface

Class to Perform Network Request

Create Operation

Read Operation

List Layout

Custom Adapter Class

Retrieving Heroes from the Database

Update Operation

Delete Operation

The complete code for MainActivity

Android MySQL Tutorial – Source Code Download

Related

Checkout these tutorials as well:

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