create a main.xml layout and Add a button for crud in the location: layout(android studio)

<?xml version="1.0" encoding="utf-8"? >
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >


    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:orientation="vertical" >


        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="426dp" >

            <TextView
                android:id="@+id/textView1"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignParentTop="true"
                android:layout_centerHorizontal="true"
                android:text="Welcome to main activity "
                android:textColor="#ffffff"
                android:textSize="15sp" />

            <Button
                android:id="@+id/btnDatabaseSqlite"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_alignLeft="@+id/btn_intent_explicit"
                android:layout_below="@+id/btn_intent_explicit"
                android:text="Database SqLite"
                android:textSize="8sp" />

          

        </RelativeLayout>

    </LinearLayout>

</LinearLayout>

create a ProjectonOverallClassMainActivity activity for crud

package com.uk.modak;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class ProjectonOverallClassMainActivity extends Activity {
   
	
	public Button btnDatabaseSqlite;
		
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
               
        btnDatabaseSqlite = (Button) findViewById(R.id.btnDatabaseSqlite);           
         btnDatabaseSqlite.setOnClickListener(new View.OnClickListener() {
    		
			public void onClick(View v) {				
				Intent b = new Intent(ProjectonOverallClassMainActivity.this,SqliteDatabaseHomeActivity.class);
				startActivity(b);
			}
	    });                      
    }
    
    public void onStart(){
    	super.onStart();
    	 	
    }
      
    
}

create a addeditupdatelayout.xml layout for crud in the location: layout(android studio)

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


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


        <TextView
            android:id="@+id/textView1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_alignParentTop="true"
            android:layout_marginTop="19dp"
            android:text="Name :" />

        <TextView
            android:id="@+id/textView2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_below="@+id/textView1"
            android:layout_marginTop="32dp"
            android:text="Surname :" />

        <EditText
            android:id="@+id/editText_name"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/textView1"
            android:layout_alignBottom="@+id/textView1"
            android:layout_alignParentRight="true"
            android:ems="10"
            android:inputType="textPersonName" />

        <EditText
            android:id="@+id/editText_surname"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/textView2"
            android:layout_alignParentRight="true"
            android:ems="10"
            android:inputType="textPersonName" />

        <TextView
            android:id="@+id/textView3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_below="@+id/textView2"
            android:layout_marginTop="35dp"
            android:text="Marks :" />

        <EditText
            android:id="@+id/editText_Marks"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/textView3"
            android:layout_alignParentRight="true"
            android:ems="10"
            android:inputType="textPersonName" />

        <TextView
            android:id="@+id/textView4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignParentLeft="true"
            android:layout_below="@+id/textView3"
            android:layout_marginTop="32dp"
            android:text="Id :" />

        <EditText
            android:id="@+id/editText_id"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBottom="@+id/textView4"
            android:layout_alignParentRight="true"
            android:ems="10"
            android:inputType="textPersonName" />

        <Button
            android:id="@+id/button_add"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/textView4"
            android:layout_marginTop="67dp"
            android:layout_toRightOf="@+id/textView4"
            android:text="Add " />

        <Button
            android:id="@+id/button_viewAll"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/button_add"
            android:layout_alignBottom="@+id/button_add"
            android:layout_toRightOf="@+id/button_add"
            android:text="View" />


        <Button
            android:id="@+id/button_update"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/button_viewAll"
            android:layout_alignBottom="@+id/button_viewAll"
            android:layout_toRightOf="@+id/button_viewAll"
            android:text="Update" />

        <Button
            android:id="@+id/button_delete"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_alignBaseline="@+id/button_update"
            android:layout_alignBottom="@+id/button_update"
            android:layout_toRightOf="@+id/button_update"
            android:text="Delete" />

    </RelativeLayout>

</LinearLayout>

create an activity in the location: src/main/java/com/uk/modak/SqliteDatabaseHomeActivity (android studio)

package com.uk.modak;

import android.app.AlertDialog;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import android.app.Activity;

public class SqliteDatabaseHomeActivity extends Activity {
	
	DatabaseHelper myDb;
    EditText editName,editSurname,editMarks ,editTextId;
    Button btnAddData;
    Button btnviewAll;
    Button btnDelete;
 
    Button btnviewUpdate;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.addeditupdatelayout);
        myDb = new DatabaseHelper(this);
 
        editName = (EditText)findViewById(R.id.editText_name);
        editSurname = (EditText)findViewById(R.id.editText_surname);
        editMarks = (EditText)findViewById(R.id.editText_Marks);
        editTextId = (EditText)findViewById(R.id.editText_id);
        btnAddData = (Button)findViewById(R.id.button_add);
        btnviewAll = (Button)findViewById(R.id.button_viewAll);
        btnviewUpdate= (Button)findViewById(R.id.button_update);
        btnDelete= (Button)findViewById(R.id.button_delete);
        AddData();
        viewAll();
        UpdateData();
        DeleteData();
    }
    public void DeleteData() {
        btnDelete.setOnClickListener(
                new View.OnClickListener() {
                  
                    public void onClick(View v) {
                        Integer deletedRows = myDb.deleteData(editTextId.getText().toString());
                        if(deletedRows > 0)
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data Deleted",Toast.LENGTH_LONG).show();
                        else
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data not Deleted",Toast.LENGTH_LONG).show();
                    }
                }
        );
    }
    public void UpdateData() {
        btnviewUpdate.setOnClickListener(
                new View.OnClickListener() {
                   
                    public void onClick(View v) {
                        boolean isUpdate = myDb.updateData(editTextId.getText().toString(),
                                editName.getText().toString(),
                                editSurname.getText().toString(),editMarks.getText().toString());
                        if(isUpdate == true)
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data Update",Toast.LENGTH_LONG).show();
                        else
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data not Updated",Toast.LENGTH_LONG).show();
                    }
                }
        );
    }
    public  void AddData() {
        btnAddData.setOnClickListener(
                new View.OnClickListener() {
                   
                    public void onClick(View v) {
                       boolean isInserted = myDb.insertData(editName.getText().toString(),
                                editSurname.getText().toString(),
                                editMarks.getText().toString() );
                        if(isInserted == true)
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data Inserted",Toast.LENGTH_LONG).show();
                        else
                            Toast.makeText(SqliteDatabaseHomeActivity.this,"Data not Inserted",Toast.LENGTH_LONG).show();
                    }
                }
        );
    }
 
    public void viewAll() {
        btnviewAll.setOnClickListener(
                new View.OnClickListener() {
                   
                    public void onClick(View v) {
                       Cursor res = myDb.getAllData();
                        if(res.getCount() == 0) {
                            // show message
                            showMessage("Error","Nothing found");
                            return;
                        }
 
                        StringBuffer buffer = new StringBuffer();
                        while (res.moveToNext()) {
                            buffer.append("Id :"+ res.getString(0)+"\n");
                            buffer.append("Name :"+ res.getString(1)+"\n");
                            buffer.append("Surname :"+ res.getString(2)+"\n");
                            buffer.append("Marks :"+ res.getString(3)+"\n\n");
                        }
 
                        // Show all data
                        showMessage("Data",buffer.toString());
                    }
                }
        );
    }
 
    public void showMessage(String title,String Message){
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setCancelable(true);
        builder.setTitle(title);
        builder.setMessage(Message);
        builder.show();
    }
 
   

}

add database helper class (android studio)

package com.uk.modak;

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

public class DatabaseHelper extends SQLiteOpenHelper {

	public static final String DATABASE_NAME = "Student.db";
    public static final String TABLE_NAME = "student_table";
    public static final String COL_1 = "ID";
    public static final String COL_2 = "NAME";
    public static final String COL_3 = "SURNAME";
    public static final String COL_4 = "MARKS";
 
    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
    }
 
    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("create table " + TABLE_NAME +" (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME TEXT,SURNAME TEXT,MARKS INTEGER)");
    }
 
    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
        onCreate(db);
    }
 
    public boolean insertData(String name,String surname,String marks) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,surname);
        contentValues.put(COL_4,marks);
        long result = db.insert(TABLE_NAME,null ,contentValues);
        if(result == -1)
            return false;
        else
            return true;
    }
 
    public Cursor getAllData() {
        SQLiteDatabase db = this.getWritableDatabase();
        Cursor res = db.rawQuery("select * from "+TABLE_NAME,null);
        return res;
    }
 
    public boolean updateData(String id,String name,String surname,String marks) {
        SQLiteDatabase db = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put(COL_1,id);
        contentValues.put(COL_2,name);
        contentValues.put(COL_3,surname);
        contentValues.put(COL_4,marks);
        db.update(TABLE_NAME, contentValues, "ID = ?",new String[] { id });
        return true;
    }
 
    public Integer deleteData (String id) {
        SQLiteDatabase db = this.getWritableDatabase();
        return db.delete(TABLE_NAME, "ID = ?",new String[] {id});
    }

}

to to menifeast and setup activity that we use

<application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name" >
        <activity
            android:name=".ProjectonOverallClassMainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
       
          <activity
            android:name=".SqliteDatabaseHomeActivity"
            android:label="@string/app_name" >
        </activity>
        
        <receiver android:name=".ConnectionReceive">
            <intent-filter>
                <action android:name="android.net.conn.CONNECTIVITY_CHANGE" />
            </intent-filter>
        </receiver>
        
    </application>