Android MySQL - Spinner - INSERT,SELECT,SHOW

android networking android crud

Android MySQL Tutorial with Spinner. How to Insert, Select then Show data From MySQL into Spinner widget.

  • Lets see how to perform basic data entry and retrieval into MySQL database from our android app.
  • First we insert multi-column data to MySQL from android.
  • Then we retrieve this data and bind it to our spinner component.
  • We are using Fast Networking Library to make our network calls.
  • It shall be returning us JSON responses in form of JSON,hence we can easily parse this data bind to spinner.
  • All network calls happen in the background thread as the library abstracts these for us.

What is a Database?

A database, generally speaking, refers to any organized collection of data

There are several types of databases:

  1. Flat file databases ― these store data sequentially, often in plain text files.

  2. Hierarchical databases ― these organize data in parent/child relationships.

  3. Key-value/document-oriented databases ― these store free-form data indexed by a key or hash value.

  4. Relational databases ― these organize data in rows and tables. This is the most popular and is what we use in most of our examples.

What is MySQL ?

MySQL is an open source, multithreaded, relational database management system created by Michael "Monty" Widenius in 1995.

Many businesses these days develop and maintain custom software with MySQL. Additionally, majority of the most popular websites(e.g Wikipedia) and software use MySQL for their database.

One of the most prominent features of MySQL is its speed and scalability. Together with MariaDB, MySQL's identical twin brother/sister, tends of thousands of rows and billions of rows of data can efficiently be handled.

However, you can also use MySQL for small amounts of data, like we will do to store our PDF documents in this android pdf viewer app we will create.

Why do Alot of People Choose MySQL?

There are many RDBMS(Relational Database Management System) databases. However MySQL is the most popular.

This is because of the following factors:

  1. Speed. MySQL is fast. Its developers claim that MySQL is about the fastest database system you can get.You can investigate this claim by visiting here, a performance-comparison page on the MySQL Web site.

  2. Ease of use. Even though MySQL is highly performant, it's relative a simple database system. Setting it up and Administering it is much less complex than other large systems.

  3. Query language support. MySQL also provides support for SQL(Structured Query Language). SQL is the standard language of choice for almost all modern database systems.

  4. Capability. The MySQL server is multi-threaded. This implies that many clients can connect to it at the same time. Each client can use multiple databases simultaneously.

  5. Connectivity and security. MySQL is fully networked, and databases can be accessed from anywhere on the Internet. Hence you can share your data with anyone, anywhere. But MySQL has access control so that one person who shouldn’t see another’s data cannot.To provide additional security, MySQL supports encrypted connections using the Secure Sockets Layer (SSL) protocol.

  6. Availability and cost. MySQL is an Open Source project available under multiple licensing terms. First, it is available under the terms of the GNU General Public License (GPL).This means that MySQL is available without cost for most in-house uses. Second, for organizations that prefer or require formal arrangements or that do not want to be bound by the conditions of the GPL, commercial licenses are available.

What is MySQLi?

MySQLi is a PHP extension which allows us to access the functionality provided by MySQL 4.1 and above.

As an extension, mysqli exposes APIs to the PHP programmer, to allow us work with MySQL database programmatically.

Normally there are three ways(APIs) of working with MySQL from database:

  1. PHP MySQLi extension.
  2. PHP MySQL extension.
  3. PHP Data Objects(PDO).

In this class we will use the most commonly used API which is mysqli.

Advantages of MySQLi

MySQLi is the most popular API for working with MySQL database because of the following reasons:

  1. Provision of both Object Oriented and Procedural Interfaces.
  2. Embedded Server support.
  3. Support for Prepared Statements.
  4. Ability to use Multiple Statements.
  5. Transactions support.

etc

You can find more information about mysqli here.

Introduction to PHP?

PHP is a popular general-purpose scripting language that is especially suited to web development.

Fast, flexible and pragmatic, PHP powers everything from your blog to the most popular websites in the world.

PHP Hello World
<?php
echo "Hello world";

PHP's website is here.

Classes

Class definitions start with the keyword class, followed by a class identifier, followed by a pair of curly braces which enclose the definitions of the properties and methods belonging to the class.

A class may contain its own constants, variables (called "properties"), and functions (called "methods").

Here's a simple class definition in PHP:

<?php
class HelloClass
{
    // property declaration
    public $var = 'a default value';

    // method declaration
    public function displayVar() {
        echo $this->var;
    }
}
?>

You can then create an instance:

<?php
$h = new HelloClass();

// This can also be done with a variable:
$className = 'HelloClass';
$h = new $className(); // new HelloClass()
?>

We will be working with PHP in an Object Oriented manner.

What is Spinner?

Spinner is a view that displays items in a dropdown fashion, allowing user to pick one at a time.

Android Spinner

Spinner is an AdapterView. This means that it relies on an Adapter for its data.

Adapters act as the bridge between adapterviews and the underlying data source.

This makes Spinner like other adapterviews decoupled from data source. Hence we can customize the views shown in the spinner without affecting data.

Spinner is a concrete public class residing in the android.widget package.

package android.widget;

Spinner is a public class that's why we can access and use it.

public class Spinner{}

Public classes are visible even from other packages apart from those they've been defined.

Spinner class inherits from an abstract class called AbsSpinner. This class also resides in the android.widget package.

AbsSpinner provides to Spinner much of the capabilities it has. For example, Spinner is an adapterview since it derives from the AbsSpinner. This allows Spinner to set and return a SpinnerAdapter.

Video Tutorial(ProgrammingWizards TV Channel)

Well we have a video tutorial as an alternative to this. If you prefer tutorials like this one then it would be good you subscribe to our YouTube channel.

Basically we have a TV for programming where do daily tutorials especially android.

Full Code - Android Spinner MySQL

Look,the full source code is available for download above.We have included the PHP code we used.Modfiy things like database name and table name of course and save the PHP in your server's root directory.

We shall then need the url to that PHP code as you shall see in our MySQL client class. Moreover,if you are stuck,check our video tutorial below.Its detailed and step by step everything. Lets see our data object,our POJO class.   Android Spinner MySQL

Our MySQL Table Structure

Create a database table.

Android Spinner MySQL

1. PHP Code

Here are our php code:

(a) Constants.php
<?php

class Constants
{
    //DATABASE DETAILS
    static $DB_SERVER="localhost";
    static $DB_NAME="galileoDB";
    static $USERNAME="root";
    static $PASSWORD="";
    const TB_NAME="galileoTB";
    //STATEMENTS
    static $SQL_SELECT_ALL="SELECT * FROM galileoTB";
}
(b) CRUD.php
<?php

require_once("/DBAdapter.php");
if($_POST['action']=="save"){

         $dbAdapter=new DBAdapter();
         $name=$_POST['name'];
         $propellant=$_POST['propellant'];
         $destination=$_POST['destination'];
        $dbAdapter->insert(array($name,$propellant,$destination));
}else if($_POST['action']=="update")
{
         $dbAdapter=new DBAdapter();
         $id=$_POST['id'];
         $name=$_POST['name'];
         $propellant=$_POST['propellant'];
         $destination=$_POST['destination'];
        $dbAdapter->update($id,array($name,$propellant,$destination));

}else if($_POST['action']=="delete")
{
         $dbAdapter=new DBAdapter();
         $id=$_POST['id'];

        $dbAdapter->delete($id);
}
?>
(c) DBAdapter.php
<?php

require_once("/Constants.php");
class DBAdapter
{
/*******************************************************************************************************************************************/
/*
   1.CONNECT TO DATABASE.
   2. RETURN CONNECTION OBJECT
*/
    public function connect()
    {

       $con=mysqli_connect(Constants::$DB_SERVER,Constants::$USERNAME,Constants::$PASSWORD,Constants::$DB_NAME);
        if(mysqli_connect_error(!$con))
        {
           // echo "Unable To Connect";
            return null;
        }else
        {

            return $con;
        }
    }
    /*******************************************************************************************************************************************/
/*
   1.INSERT SPACECRAFT INTO DATABASE
 */
    public function insert($s)
    {
        // INSERT
        $con=$this->connect();

        if($con != null)
        {
            $sql="INSERT INTO galileoTB(name,propellant,destination) VALUES('$s[0]','$s[1]','$s[2]')";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Success")));
                }else
                {
                    print(json_encode(array("Unsuccessfull")));
                }
            }catch (Exception $e)
            {
               print(json_encode(array("PHP EXCEPTION : CAN'T SAVE TO MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.SELECT FROM DATABASE.
*/
    public function select()
    {
       $con=$this->connect();
        if($con != null)
        {
            $retrieved=mysqli_query($con,Constants::$SQL_SELECT_ALL);
            if($retrieved)
            {
                while($row=mysqli_fetch_array($retrieved))
                {

                   // echo $row["name"] ,"    \t | ",$row["propellant"],"</br>";
                   $spacecrafts[]=$row;
                }
                print(json_encode($spacecrafts));
            }else
            {
                 print(json_encode(array("PHP EXCEPTION : CAN'T RETRIEVE FROM MYSQL. ")));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.UPDATE  DATABASE.

*/
    public function update($id, $s)
    {
        // UPDATE
        $con=$this->connect();

        if($con != null)
        {
            $sql="UPDATE galileoTB SET name='$s[0]',propellant='$s[1]',destination='$s[2]' WHERE id='$id'";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Successfully Updated")));
                }else
                {
                    print(json_encode(array("Not Successfully Updated")));
                }
            }catch (Exception $e)
            {
                 print(json_encode(array("PHP EXCEPTION : CAN'T UPDATE INTO MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }
/*******************************************************************************************************************************************/
/*
   1.DELETE SPACECRAFT FROM DATABASE.

*/
    public function delete($id)
    {
        $con=$this->connect();

        if($con != null)
        {
//            $name=$_POST['Name'];
//            $pos=$_POST['Position'];
//            $team=$_POST['Team'];
            $sql="DELETE FROM galileoTB WHERE id='$id'";
            try
            {
                $result=mysqli_query($con,$sql);
                if($result)
                {
                    print(json_encode(array("Successfully Deleted")));
                }else
                {
                    print(json_encode(array("Not Successfully Deleted")));
                }
            }catch (Exception $e)
            {
                print(json_encode(array("PHP EXCEPTION : CAN'T DELETE FROM MYSQL. "+$e->getMessage())));
            }
        }else{
            print(json_encode(array("PHP EXCEPTION : CAN'T CONNECT TO MYSQL. NULL CONNECTION.")));
        }
        mysqli_close($con);
    }

}
(d) Index.php
<?php

require_once("/DBAdapter.php");
    $dbAdapter=new DBAdapter();
    $dbAdapter->select();
?>

2. Gradle Scripts

Here are our gradle scripts in our build.gradle file(s).

(a). build.gradle(app)

Here's our app level build.gradle file. We have the dependencies DSL where we add our dependencies.

This file is called app level build.gradle since it's located in the app folder of the project.

If you are using Android Studio version 3 and above use implementation keyword while if you are using a version less than 3 then still use the compile keyword.

Once you've modified this build.gradle file you have to sync your project. Android Studio will indeed prompt you to do so.

dependencies {
    compile fileTree(dir: 'libs', include: ['*.jar'])
    testCompile 'junit:junit:4.12'
    compile 'com.android.support:appcompat-v7:24.2.0'
    compile 'com.android.support:design:24.2.0'
    compile 'com.amitshekhar.android:android-networking:0.2.0'
}

We are using Fast Android Networking Library as our HTTP Client. You may use newer versions.

Java Code.

Android apps can be mainly written in Java or Kotlin. These days however there are many frameworks like Flutter also which use languages like Dart.

In this class we are using Java programming language.

We will have these classes in our project.

(a). Spacecraft.java
package com.tutorials.hp.spinnermysql.mModel;

public class Spacecraft {

    /*
    INSTANCE FIELDS
     */
    private int id;
    private String name;
    private String propellant;
    private String destination;

    /*
    GETTERS AND SETTERS
     */
    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getPropellant() {
        return propellant;
    }

    public void setPropellant(String propellant) {
        this.propellant = propellant;
    }

    public String getDestination() {
        return destination;
    }

    public void setDestination(String destination) {
        this.destination = destination;
    }

    /*
    TOSTRING
     */
    @Override
    public String toString() {
        return name;
    }
}
(b). MySQLClient.java

Then we have our most important class,our MySQL Client class.Its where we make calls to our server and perform CRUD activities.Take note of the URLs pointing us to PHP code.  

package com.tutorials.hp.spinnermysql.mMySQL;

import android.content.Context;
import android.widget.ArrayAdapter;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;

import com.androidnetworking.AndroidNetworking;
import com.androidnetworking.common.Priority;
import com.androidnetworking.error.ANError;
import com.androidnetworking.interfaces.JSONArrayRequestListener;
import com.tutorials.hp.spinnermysql.mModel.Spacecraft;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class MySQLClient {

    //SAVE/RETRIEVE URLS
    private static final String DATA_INSERT_URL="http://10.0.2.2/android/GalacticCity/crud.php";
    private static final String DATA_RETRIEVE_URL="http://10.0.2.2/android/GalacticCity/index.php";

    //INSTANCE FIELDS
    private final Context c;
    private ArrayAdapter<Spacecraft> adapter ;

    public MySQLClient(Context c) {
        this.c = c;

    }
    /*
    SAVE/INSERT
     */
    public void add(Spacecraft s, final EditText...editTexts)
    {
        if(s==null)
        {
            Toast.makeText(c, "No Data To Save", Toast.LENGTH_SHORT).show();
        }
            else
        {
            AndroidNetworking.post(DATA_INSERT_URL)
                    .addBodyParameter("action","save")
                    .addBodyParameter("name",s.getName())
                    .addBodyParameter("propellant",s.getPropellant())
                    .addBodyParameter("destination",s.getDestination())
                    .setTag("TAG_ADD")
                    .build()
                    .getAsJSONArray(new JSONArrayRequestListener() {
                        @Override
                        public void onResponse(JSONArray response) {

                            if(response != null)
                                try {
                                    //SHOW RESPONSE FROM SERVER
                                    String responseString = response.get(0).toString();
                                    Toast.makeText(c, "PHP SERVER RESPONSE : " + responseString, Toast.LENGTH_SHORT).show();

                                    if (responseString.equalsIgnoreCase("Success")) {
                                        //CLEAR EDITXTS
                                        EditText nameTxt = editTexts[0];
                                        EditText propTxt = editTexts[1];
                                        EditText destTxt = editTexts[2];

                                        nameTxt.setText("");
                                        propTxt.setText("");
                                        destTxt.setText("");
                                    }else
                                    {
                                        Toast.makeText(c, "PHP WASN'T SUCCESSFUL. ", Toast.LENGTH_SHORT).show();

                                    }

                                } catch (JSONException e) {
                                    e.printStackTrace();
                                    Toast.makeText(c, "GOOD RESPONSE BUT JAVA CAN'T PARSE JSON IT RECEIVED : "+e.getMessage(), Toast.LENGTH_SHORT).show();
                                }

                        }

                        //ERROR
                        @Override
                        public void onError(ANError anError) {
                            Toast.makeText(c, "UNSUCCESSFUL :  ERROR IS : "+anError.getMessage(), Toast.LENGTH_SHORT).show();
                        }

                    });

        }
    }

    /*
    RETRIEVE/SELECT/REFRESH
     */
    public void retrieve(final Spinner sp)
    {
        final ArrayList<Spacecraft> spacecrafts = new ArrayList<>();

        AndroidNetworking.get(DATA_RETRIEVE_URL)
                .setPriority(Priority.HIGH)
                .build()
                .getAsJSONArray(new JSONArrayRequestListener() {
                    @Override
                    public void onResponse(JSONArray response) {
                        JSONObject jo;
                        Spacecraft s;
                        try
                        {
                            for(int i=0;i<response.length();i++)
                            {
                                jo=response.getJSONObject(i);

                                int id=jo.getInt("id");
                                String name=jo.getString("name");
                                String propellant=jo.getString("propellant");
                                String destination=jo.getString("destination");

                                s=new Spacecraft();
                                s.setId(id);
                                s.setName(name);
                                s.setPropellant(propellant);
                                s.setDestination(destination);

                                spacecrafts.add(s);
                            }

                            //SET TO SPINNER
                            adapter =new ArrayAdapter(c,android.R.layout.simple_list_item_1,spacecrafts);
                            sp.setAdapter(adapter);

                        }catch (JSONException e)
                        {
                            Toast.makeText(c, "GOOD RESPONSE BUT JAVA CAN'T PARSE JSON IT RECEIEVED. "+e.getMessage(), Toast.LENGTH_LONG).show();

                        }

                    }

                    //ERROR
                    @Override
                    public void onError(ANError anError) {
                        anError.printStackTrace();
                        Toast.makeText(c, "UNSUCCESSFUL :  ERROR IS : "+anError.getMessage(), Toast.LENGTH_LONG).show();

                    }
                });
    }
}
(d). MainActivity.java

This is our launcher activity as the name suggests. This means it will be the main entry point to our app in that when the user clicks the icon for our app, this activity will get rendered first.

We override a method called onCreate(). Here we will start by inflating our main layout via the setContentView() method.

Our main activity is actually an activity since it's deriving from the AppCompatActivity.

Finally our MainActivity is here :  

package com.tutorials.hp.spinnermysql;

import android.os.Bundle;
import android.support.design.widget.TextInputEditText;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.widget.Button;
import android.widget.Spinner;
import android.widget.Toast;

import com.tutorials.hp.spinnermysql.mModel.Spacecraft;
import com.tutorials.hp.spinnermysql.mMySQL.MySQLClient;

public class MainActivity extends AppCompatActivity {

    //INSTANCE FIELDS
    private TextInputEditText txtName,txtPropellant,txtDestination;
    private Spinner sp;
    private Button btnAdd,btnRetrieve;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        //REFERENCE VIEWS
        this.initializeViews();

        //HANDLE EVENTS
        this.handleClickEvents();

    }

    /*
    REFERENCE VIEWS
     */
    private void initializeViews()
    {

        txtName= (TextInputEditText) findViewById(R.id.nameTxt);
        txtPropellant= (TextInputEditText) findViewById(R.id.propellantTxt);
        txtDestination= (TextInputEditText) findViewById(R.id.destinationTxt);

        btnAdd= (Button) findViewById(R.id.addBtn);
        btnRetrieve= (Button) findViewById(R.id.refreshBtn);

        sp= (Spinner) findViewById(R.id.sp);

    }

    /*
    HANDLE CLICK EVENTS
     */
    private void handleClickEvents()
    {
        //EVENTS : ADD
        btnAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //GET VALUES
                String name=txtName.getText().toString();
                String propellant=txtPropellant.getText().toString();
                String destination=txtDestination.getText().toString();

                //BASIC CLIENT SIDE VALIDATION
                if((name.length()<1 || propellant.length()<1 || destination.length()<1 ))
                {
                    Toast.makeText(MainActivity.this, "Please Enter all Fields", Toast.LENGTH_SHORT).show();
                }
                else
                {
                    //SAVE

                    Spacecraft s=new Spacecraft();
                    s.setName(name);
                    s.setPropellant(propellant);
                    s.setDestination(destination);

                    new MySQLClient(MainActivity.this).add(s,txtName,txtPropellant,txtDestination);
                }
            }
        });

        //EVENTS : RETRIEVE
        btnRetrieve.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                new MySQLClient(MainActivity.this).retrieve(sp);

            }
        });

    }
}

Download

Hey,everything is in source code reference that is well commented and easy to understand and can be downloaded below.

Also check our video tutorial it's more detailed and explained in step by step.

No. Location Link
1. GitHub Direct Download
2. GitHub Browse
3. YouTube Video Tutorial

About Me

My name is Oclemy, after recently finishing my Software Engineering undergraduate program, am now dedicating alot of time to my two babies: Camposha.info and my YouTube Channel ProgrammingWizards TV apart from my daily work.

Am committed to making them world class resources in the next few years. Help me by subscribing to my YouTube Channel ProgrammingWizards TV and sharing my articles.

Best Regards,

Oclemy.

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