1. Home
  2. Read Data Operation

Read Data Operation

In the upper part, we have created a PHP script for reading the data from the SQL table. In this part, we will integrate that in our Android App and read data to our SQL table from our Android app. 

What we are going to build in this article? 

We will be building a simple application in which we will be reading data from our SQL table by passing the ID. We will be reading this data using PHP scripts that we have created earlier. Below is the video in which we will get to see what we are going to build in this article. 

Step by Step Implementation

Step 1: Create a New Project

To create a new project in Android Studio please refer to How to Create/Start a New Project in Android Studio. Note that select Java as the programming language.

Step 2: Add the below dependency in your build.gradle file

Below is the dependency for Volley which we will be using to get the data from API. For adding this dependency navigate to the app > Gradle Scripts > build.gradle(app) and add the below dependency in the dependencies section. 

implementation ‘com.android.volley:volley:1.1.1’

After adding this dependency sync your project and now move towards the AndroidManifest.xml part.  

Step 3: Adding permissions to the internet in the AndroidManifest.xml file

Navigate to the app > AndroidManifest.xml and add the below code to it.   

XML




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






                        









									
									
								

								
								

									
									
Step 4: Working with the activity_main.xml file

									
									
								

								
								

									
									
Navigate to the app > res > layout > activity_main.xml and add the below code to that file. Below is the code for the activity_main.xml file. 

									
									
								

								
								

									
									




XML















                                    




                                    

                                    




                                    




                                    

                                    

                                    
                                




















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


<LinearLayout


    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"


    android:orientation="vertical"


    tools:context=".MainActivity">


 


    <!--Edit text for getting course id-->


    <EditText


        android:id="@+id/idEdtCourseId"


        android:layout_width="match_parent"


        android:layout_height="wrap_content"


        android:layout_marginStart="10dp"


        android:layout_marginTop="20dp"


        android:layout_marginEnd="10dp"


        android:hint="Enter Course Id"


        android:importantForAutofill="no"


        android:inputType="number" />


 


    <!--Button for adding your course to Firebase-->


    <Button


        android:id="@+id/idBtnGetCourse"


        android:layout_width="match_parent"


        android:layout_height="wrap_content"


        android:layout_margin="10dp"


        android:text="Get Course Details"


        android:textAllCaps="false" />


 


    <androidx.cardview.widget.CardView


        xmlns:app="http://schemas.android.com/apk/res-auto"


        android:id="@+id/idCVCOurseItem"


        android:layout_width="match_parent"


        android:layout_height="wrap_content"


        android:layout_margin="5dp"


        android:visibility="gone"


        app:cardCornerRadius="6dp"


        app:cardElevation="4dp">


 


        <LinearLayout


            android:layout_width="match_parent"


            android:layout_height="wrap_content"


            android:layout_margin="2dp"


            android:orientation="vertical"


            android:padding="4dp">


             


            <!--Textview for displaying our Course Name-->


            <TextView


                android:id="@+id/idTVCourseName"


                android:layout_width="match_parent"


                android:layout_height="wrap_content"


                android:padding="2dp"


                android:text="CourseName"


                android:textColor="@color/purple_500"


                android:textSize="18sp"


                android:textStyle="bold" />


             


            <!--Textview for displaying our Course Duration-->


            <TextView


                android:id="@+id/idTVCourseDuration"


                android:layout_width="match_parent"


                android:layout_height="wrap_content"


                android:padding="2dp"


                android:text="Duration"


                android:textColor="@color/black" />


             


            <!--Textview for displaying our Course Description-->


            <TextView


                android:id="@+id/idTVCourseDescription"


                android:layout_width="match_parent"


                android:layout_height="wrap_content"


                android:padding="2dp"


                android:text="Description"


                android:textColor="@color/black" />


        </LinearLayout>


         


    </androidx.cardview.widget.CardView>


     


</LinearLayout>



















                        







                        









									
									
								

								
								

									
									
Step 5: Working with the MainActivity.java file

									
									
								

								
								

									
									
Go to the MainActivity.java file and refer to the following code. Below is the code for the MainActivity.java file. Comments are added inside the code to understand the code in more detail.

									
									
								

								
								

									
									




Java















                                    




                                    

                                    




                                    




                                    

                                    

                                    
                                




















import android.os.Bundle;


import android.text.TextUtils;


import android.view.View;


import android.widget.Button;


import android.widget.EditText;


import android.widget.TextView;


import android.widget.Toast;


 


import androidx.appcompat.app.AppCompatActivity;


import androidx.cardview.widget.CardView;


 


import com.android.volley.Request;


import com.android.volley.RequestQueue;


import com.android.volley.VolleyError;


import com.android.volley.toolbox.StringRequest;


import com.android.volley.toolbox.Volley;


 


import org.json.JSONException;


import org.json.JSONObject;


 


import java.util.HashMap;


import java.util.Map;


 


public class MainActivity extends AppCompatActivity {


     


    // creating variables for our edit text


    private EditText courseIDEdt;


     


    // creating variable for button


    private Button getCourseDetailsBtn;


     


    // creating variable for card view and text views.


    private CardView courseCV;


    private TextView courseNameTV, courseDescTV, courseDurationTV;


 


    @Override


    protected void onCreate(Bundle savedInstanceState) {


        super.onCreate(savedInstanceState);


        setContentView(R.layout.activity_main);


         


        // initializing all our variables.


        courseNameTV = findViewById(R.id.idTVCourseName);


        courseDescTV = findViewById(R.id.idTVCourseDescription);


        courseDurationTV = findViewById(R.id.idTVCourseDuration);


        getCourseDetailsBtn = findViewById(R.id.idBtnGetCourse);


        courseIDEdt = findViewById(R.id.idEdtCourseId);


        courseCV = findViewById(R.id.idCVCOurseItem);


         


        // adding click listener for our button.


        getCourseDetailsBtn.setOnClickListener(new View.OnClickListener() {


            @Override


            public void onClick(View v) {


                // checking if the id text field is empty or not.


                if (TextUtils.isEmpty(courseIDEdt.getText().toString())) {


                    Toast.makeText(MainActivity.this, "Please enter course id", Toast.LENGTH_SHORT).show();


                    return;


                }


                // calling method to load data.


                getCourseDetails(courseIDEdt.getText().toString());


            }


        });


    }


 


    private void getCourseDetails(String courseId) {


         


        // url to post our data


        String url = "http://localhost/courseApp/readCourses.php";


         


        // creating a new variable for our request queue


        RequestQueue queue = Volley.newRequestQueue(MainActivity.this);


         


        // on below line we are calling a string 


        // request method to post the data to our API


        // in this we are calling a post method.


        StringRequest request = new StringRequest(Request.Method.POST, url, new com.android.volley.Response.Listener<String>() {


            @Override


            public void onResponse(String response) {


                try {


                    // on below line passing our response to json object.


                    JSONObject jsonObject = new JSONObject(response);


                    // on below line we are checking if the response is null or not.


                    if (jsonObject.getString("courseName") == null) {


                        // displaying a toast message if we get error


                        Toast.makeText(MainActivity.this, "Please enter valid id.", Toast.LENGTH_SHORT).show();


                    } else {


                        // if we get the data then we are setting it in our text views in below line.


                        courseNameTV.setText(jsonObject.getString("courseName"));


                        courseDescTV.setText(jsonObject.getString("courseDescription"));


                        courseDurationTV.setText(jsonObject.getString("courseDuration"));


                        courseCV.setVisibility(View.VISIBLE);


                    }


                    // on below line we are displaying


                    // a success toast message.


                } catch (JSONException e) {


                    e.printStackTrace();


                }


            }


        }, new com.android.volley.Response.ErrorListener() {


            @Override


            public void onErrorResponse(VolleyError error) {


                // method to handle errors.


                Toast.makeText(MainActivity.this, "Fail to get course" + error, Toast.LENGTH_SHORT).show();


            }


        }) {


            @Override


            public String getBodyContentType() {


                // as we are passing data in the form of url encoded 


                // so we are passing the content type below


                return "application/x-www-form-urlencoded; charset=UTF-8";


            }


 


            @Override


            protected Map<String, String> getParams() {


                


                // below line we are creating a map for storing our values in key and value pair.


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


                 


                // on below line we are passing our key and value pair to our parameters.


                params.put("id", courseId);


                 


                // at last we are returning our params.


                return params;


            }


        };


        // below line is to make 


        // a json object request.


        queue.add(request);


    }


}



















                        







                        









									
									
								

								
								

									
									
Now run your app and see the output of the code. 

									
									
								

								
								

									
									
Output: 

									
									
								

								
								

									
									

									
									
								

								
								

									
									

									
									
								

								
								

									
									

									
									
								

								
								

									
									

									
									
								

								
							

							
							

								
CRUD Operation in MySQL Using PHP, Volley Android – Read Data

								
								

									
									
In the previous article, we have performed the insert data operation. In this article, we will perform the Read data operation. Before performing this operation first of all we have to create a new PHP script for reading data from SQL Database. 

									
									
								

								
								

									
									
Prerequisite: You should be having Postman installed in your system to test this PHP script. 

									
									
								

								
							

						


						
						

							
Similar Reads

							
							

								
									

										Create a PHP script for reading data from My SQL Database

									

										We will be building a simple PHP script in which we will be used to read data from our SQL table which we have created in our previous article. Using this script we will be reading data from our SQL table....
									

								
							

							
							

								
									

										Read Data Operation

									

										...
									

								
							

							
						


					

				

				

					

						
Categories

							

								HTML
								CSS3
								Bootstrap
								Foundation
								Sass
								JavaScript
								TypeScript
								JQuery
								AngularJS
								React
								NodeJS
								Highcharts
								PHP
								Python
								Python3
								Django
								Linux
								Docker
								Ruby
								Java
								C
								C ++
								Perl
								Servlet
								JSP
								Lua
								Scala
								Go
								ASP
								C #
								SQL
								MySQL
								SQLite
								MongoDB
								Redis
								Android
								Swift
								ionic
								Kotlin
								XML tutorial
							

					

					

						
Contact US