Notes

package com.example.database;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;

import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {

// creating variables for our edittext, button and dbhandler
private EditText courseNameEdt, courseTracksEdt, courseDurationEdt, courseDescriptionEdt;
private Button addCourseBtn;
private DBHandler dbHandler;

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

// initializing all our variables.
courseNameEdt = findViewById(R.id.idEdtCourseName);
courseTracksEdt = findViewById(R.id.idEdtCourseTracks);
courseDurationEdt = findViewById(R.id.idEdtCourseDuration);
courseDescriptionEdt = findViewById(R.id.idEdtCourseDescription);
addCourseBtn = findViewById(R.id.idBtnAddCourse);

// creating a new dbhandler class
// and passing our context to it.
dbHandler = new DBHandler(MainActivity.this);

// below line is to add on click listener for our add course button.
addCourseBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {

// below line is to get data from all edit text fields.
String courseName = courseNameEdt.getText().toString();
String courseTracks = courseTracksEdt.getText().toString();
String courseDuration = courseDurationEdt.getText().toString();
String courseDescription = courseDescriptionEdt.getText().toString();

// validating if the text fields are empty or not.
if (courseName.isEmpty() && courseTracks.isEmpty() && courseDuration.isEmpty() && courseDescription.isEmpty()) {
Toast.makeText(MainActivity.this, "Please enter all the data..", Toast.LENGTH_SHORT).show();
return;
}

// on below line we are calling a method to add new
// course to sqlite data and pass all our values to it.
dbHandler.addNewCourse(courseName, courseDuration, courseDescription, courseTracks);

// after adding the data we are displaying a toast message.
Toast.makeText(MainActivity.this, "Course has been added.", Toast.LENGTH_SHORT).show();
courseNameEdt.setText("");
courseDurationEdt.setText("");
courseTracksEdt.setText("");
courseDescriptionEdt.setText("");
}
});
}
}