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

    <!--recycler view to display our data-->
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/idRVCourses"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <!--fab to add new courses-->
    <com.google.android.material.floatingactionbutton.FloatingActionButton
        android:id="@+id/idFABAdd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentEnd="true"
        android:layout_alignParentBottom="true"
        android:layout_marginStart="18dp"
        android:layout_marginTop="18dp"
        android:layout_marginEnd="18dp"
        android:layout_marginBottom="18dp"
        android:src="@android:drawable/ic_input_add"
        app:tint="@color/white" />

</RelativeLayout>

import androidx.room.Entity;
import androidx.room.PrimaryKey;

// below line is for setting table name.
@Entity(tableName = "course_table")
public class CourseModal {

    // below line is to auto increment
    // id for each course.
    @PrimaryKey(autoGenerate = true)

    // variable for our id.
    private int id;

    // below line is a variable 
    // for course name.
    private String courseName;

    // below line is use for 
    // course description.
    private String courseDescription;

    // below line is use 
    // for course duration.
    private String courseDuration;

    // below line we are creating constructor class.
    // inside constructor class we are not passing 
    // our id because it is incrementing automatically
    public CourseModal(String courseName, String courseDescription, String courseDuration) {
        this.courseName = courseName;
        this.courseDescription = courseDescription;
        this.courseDuration = courseDuration;
    }

    // on below line we are creating
    // getter and setter methods.
    public String getCourseName() {
        return courseName;
    }

    public void setCourseName(String courseName) {
        this.courseName = courseName;
    }

    public String getCourseDescription() {
        return courseDescription;
    }

    public void setCourseDescription(String courseDescription) {
        this.courseDescription = courseDescription;
    }

    public String getCourseDuration() {
        return courseDuration;
    }

    public void setCourseDuration(String courseDuration) {
        this.courseDuration = courseDuration;
    }

    public int getId() {
        return id;
    }

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