Db helper

package com.example.cse332mainproject;

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

import androidx.annotation.Nullable;

public class DBHelper extends SQLiteOpenHelper
{
    public DBHelper( Context context) {
        super(context,"Login.db", null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase myDB)
    {
        myDB.execSQL("create Table users(username Text primary key, password Text)");
    }

    @Override
    public void onUpgrade(SQLiteDatabase myDB, int i, int i1) {

    }

    public Boolean insertData(String username, String password)
    {
        SQLiteDatabase myDB = this.getWritableDatabase();
        ContentValues contentValues = new ContentValues();
        contentValues.put("username", username);
        contentValues.put("password", password);
        long result = myDB.insert("users", null, contentValues);

        if(result == -1)
        {
            return false;
        }
        else
        {
            return true;
        }

    }

    public Boolean checkusername(String username)
    {
        SQLiteDatabase myDB = this.getWritableDatabase();
        Cursor cursor = myDB.rawQuery("select * from users where username = ?", new String[] {username});

        if(cursor.getCount() > 0)
        {
            return true;
        }
        else
        {
            return false;
        }
    }

    public Boolean checkusernamePassword(String username, String password)
    {
        SQLiteDatabase myDB = this.getWritableDatabase();
        Cursor cursor = myDB.rawQuery("select * from users where username = ? and password = ?", new String[] {username, password});
        if(cursor.getCount() > 0)
        {
            return true;
        }
        else
        {
            return false;
        }

    }
}