在SQLite中验证用户名和密码

Question

我正在在Android Studio中创建一个连接到SQLite的登录名。如果用户名和密码正确（我俩都存储在数据库中），我想继续第二次活动。可以从我的管理页面添加用户，一切正常。如何检查用户名和密码是否存储在数据库中？

到目前为止，这是我的代码：

主要活动：

package com.example.schoolapp;

import android.content.Intent;
import android.se.omapi.Session;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import com.example.schoolapp.Admin.DBHelper;
import com.example.schoolapp.Admin.ThirdActivity;
import com.example.schoolapp.Eleve.SecondActivity;


public class MainActivity extends AppCompatActivity {
    DBHelper SchoolAppDB;

    //Initialisation des variables
    private EditText Name;
    private EditText Password;
    private Button Login;

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

        //Mise en relation des variables a leurs correspondants dans le fichier XML par leur ID
        Name = (EditText) findViewById(R.id.etNewName);
        Password = (EditText) findViewById(R.id.etPassword);
        Login = (Button) findViewById(R.id.btnLogin);

        Login.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {


                //getting Edit Text values and stores it into string
                String username = Name.getText().toString();
                String password = Password.getText().toString();

                //check authorized user or not

                if (SchoolAppDB.checkUser(username, password)) {
                    Intent intent =new Intent(MainActivity.this,SecondActivity.class);
                    startActivity(intent);
                    Toast.makeText(getApplicationContext(), "Login Successfull", Toast.LENGTH_LONG).show();


                } else {
                    Toast.makeText(getApplicationContext(), "Wrong Username or Password", Toast.LENGTH_LONG).show();
                }


            }

        });

    }
}

DBHelper的checkUserLogin方法：

public boolean checkUserLogin(String username,String password){
        SQLiteDatabase db=this.getWritableDatabase();
        String Query = "select USER_NAME, USER_PASSWORD from USER where USER_NAME='"+ username +"' and USER_PASSWORD='"+ password+"'";
        Cursor cursor = null;

        try {
            cursor = db.rawQuery(Query, null);//raw query always holds rawQuery(String Query,select args)
        } catch (Exception e) {
            e.printStackTrace();
        }

        if(cursor!=null && cursor.getCount()>0){
            cursor.close();
            return true;
        }
        else{
            cursor.close();
            return false;
        }

    }