Create a CRUD operation in Android Studio with source code

 Create a CRUD operation in Android Studio

We will perform create, read, update, delete operations using SQLite database. Adding data and using SQLite database will show the data in ListView.

In this blog post, a simple CRUD operation example will perform in a ListView with an SQLite database.

We will create, insert, display, edit, and delete SQLite databases in an Android listview using the SQLite OpenHelper class.

In last, the source code is also given.

First, we will create the database file named

DBmain.java

package com.pd.listviewsqlite;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;

import androidx.annotation.Nullable;

public class DBmain extends SQLiteOpenHelper {
    public DBmain(@Nullable Context context) {
        super(context, "namedb", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
String sql="create table thing(id integer primary key,name text)";
db.execSQL(sql);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
String sql="drop table if exists thing";
db.execSQL(sql);
onCreate(db);
    }
}

Now we will create a single XML view file to display data

singledata.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="wrap_content"
    android:orientation="vertical">

    <TextView
        android:id="@+id/txt_name"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="50dp"
        android:layout_marginTop="10dp"
        android:text="@string/app_name" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content">

        <ImageView
            android:id="@+id/edit_data"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentEnd="true"
            android:layout_marginTop="10dp"
            android:src="@drawable/ic_baseline_edit_24" />

        <ImageView
            android:id="@+id/delete_data"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="10dp"
            android:src="@drawable/ic_baseline_delete_24" />

    </RelativeLayout>
</RelativeLayout>

In the main activity, we will add data into the SQLite database

MainActivity.java

package com.pd.listviewsqlite;

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.Intent;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {

    private static DBmain dBmain;
    private static EditText edtname;
    private static Button submit, edit, display;
    private static SQLiteDatabase sqLiteDatabase;
    private static int id = 0;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        dBmain = new DBmain(MainActivity.this);
//create method
        findid();
        getData();
        clear();
        editData();
    }

    private void editData() {
    if (getIntent().getBundleExtra("userdata")!=null){
    Bundle bundle=getIntent().getBundleExtra("userdata");
    id=bundle.getInt("id");
    edtname.setText(bundle.getString("name"));
    edit.setVisibility(View.VISIBLE);
    submit.setVisibility(View.GONE);
    }
    }

    private void clear() {
    edtname.setText("");
    }

    private void getData() {

        submit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                ContentValues contentValues=new ContentValues();
                contentValues.put("name",edtname.getText().toString());
                sqLiteDatabase=dBmain.getWritableDatabase();
                Long recid=sqLiteDatabase.insert("thing",null,contentValues);
                if (recid!=null){
                    Toast.makeText(MainActivity.this, "Data inserted successfully", Toast.LENGTH_SHORT).show();
                    clear();
                }else{
                    Toast.makeText(MainActivity.this, "something wrong try again", Toast.LENGTH_SHORT).show();
                }

            }
        });
       // now display data
        display.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
            startActivity(new Intent(MainActivity.this,DisplayData.class));
            }
        });

        //now edit the data
        edit.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                ContentValues contentValues=new ContentValues();
                contentValues.put("name",edtname.getText().toString());

                sqLiteDatabase=dBmain.getWritableDatabase();
                long recid=sqLiteDatabase.update("thing",contentValues,"id="+id,null);

                if (recid!=-1){
                    Toast.makeText(MainActivity.this, "Data update successfully", Toast.LENGTH_SHORT).show();
                    // when successfully edit data submit button visible and edit button disapear
                    submit.setVisibility(View.VISIBLE);
                    edit.setVisibility(View.GONE);
                    clear();
                }else{
                    Toast.makeText(MainActivity.this, "something wrong try again", Toast.LENGTH_SHORT).show();
                }

            }
        });

    }

    private void findid() {
    edtname=findViewById(R.id.edtname);
    submit=findViewById(R.id.btn_submit);
    edit=findViewById(R.id.btn_edit);
    display=findViewById(R.id.btn_display);
    }
}

we can add data through this file. 

we will create the edit box and some buttons.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <EditText
        android:id="@+id/edtname"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dp"
        android:hint="Name" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_margin="10dp"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btn_submit"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="submit" />

        <Button
            android:id="@+id/btn_edit"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="submit"
            android:visibility="gone" />

        <Button
            android:id="@+id/btn_display"
            android:layout_width="0dp"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="display" />

    </LinearLayout>

</LinearLayout>

Create new activity named DispalyData.

After inserting data into SQLite,

Now we will fetch each data.

DisplayData.java

package com.pd.listviewsqlite;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;

public class DisplayData extends AppCompatActivity {
    DBmain dBmain;
    SQLiteDatabase sqLiteDatabase;
    ListView listView;
    String[] name;
    int[] id;

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

        dBmain = new DBmain(DisplayData.this);
        //create method
        findid();
        dis();

    }

    //for display data
    private void dis() {

        sqLiteDatabase = dBmain.getReadableDatabase();
        Cursor cursor = sqLiteDatabase.rawQuery("select *from thing", null);
        if (cursor.getCount() > 0) {
            id = new int[cursor.getCount()];
            name = new String[cursor.getCount()];
            int i = 0;
            while (cursor.moveToNext()) {
                id[i] = cursor.getInt(0);
                name[i] = cursor.getString(1);
                i++;
            }
            Custom adapter = new Custom();
            listView.setAdapter(adapter);
        }

    }

    private void findid() {
        listView = findViewById(R.id.listview);
    }

    private class Custom extends BaseAdapter {
        @Override
        public int getCount() {
            return name.length;
        }

        @Override
        public Object getItem(int position) {
            return null;
        }

        @Override
        public long getItemId(int position) {
            return 0;
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            TextView textView;
            ImageView edit, delete;

            convertView = LayoutInflater.from(DisplayData.this).inflate(R.layout.singledata, parent, false);
            textView = convertView.findViewById(R.id.txt_name);

            edit = convertView.findViewById(R.id.edit_data);
            delete = convertView.findViewById(R.id.delete_data);

            textView.setText(name[position]);

            edit.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    Bundle bundle = new Bundle();
                    bundle.putInt("id", id[position]);
                    bundle.putString("name", name[position]);

                    Intent intent = new Intent(DisplayData.this, MainActivity.class);
                    intent.putExtra("userdata", bundle);
                    startActivity(intent);
                }
            });

            delete.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    sqLiteDatabase = dBmain.getReadableDatabase();
                    long recd = sqLiteDatabase.delete("thing", "id=" + id[position], null);
                    if (recd != -1) {
                        Toast.makeText(DisplayData.this, "Record deleted successfully", Toast.LENGTH_SHORT).show();
                        dis();
                    }

                }
            });

            return convertView;
        }
    }
}

We will create a list file with a list view to display data

activity_display.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".DisplayData">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/listview"
        android:layout_weight="1"/>

</LinearLayout>

watch demo 

https://youtu.be/ejLEPMS3wds 

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