How do I get the maximum id from a table?

Question

How do I get the maximum id from a table? What command can I use to fix it, or do I need to write a method? Thanks for the past answers.Is my program supposed to change the last entry? Any ideas give me, I am new to android developer.Is it possible to apply db.rawQuaery somehow? Or are there other ways to change the record? '

import androidx.appcompat.app.AppCompatActivity;

import android.content.ContentValues;
import android.content.Intent;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class UserActivity<cursor> extends AppCompatActivity {

    EditText nameBox;
    EditText yearBox;
    Button delButton;
    Button saveButton;

    DatabaseHelper sqlHelper;
    SQLiteDatabase db;
    Cursor userCursor;
    long userId = 5;




    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user);

        nameBox = findViewById(R.id.name);
        yearBox = findViewById(R.id.year);
        delButton = findViewById(R.id.deleteButton);
        saveButton = findViewById(R.id.saveButton);

        sqlHelper = new DatabaseHelper(this);
        db = sqlHelper.getWritableDatabase();

        Bundle extras = getIntent().getExtras();
        if (extras != null) {
            userId = extras.getLong("id");
        }
        
        if (userId > 0) {
    
            userCursor = db.rawQuery("select * from " + DatabaseHelper.TABLE + " where " +
                    DatabaseHelper.COLUMN_ID + "=?", new String[]{String.valueOf(userId)});
            userCursor.moveToFirst();
            nameBox.setText(userCursor.getString(1));
            yearBox.setText(String.valueOf(userCursor.getInt(2)));
            userCursor.close();
        } else {
            
            delButton.setVisibility(View.GONE);
        }
    }


    public void save(View view){
        ContentValues cv = new ContentValues();
        cv.put(DatabaseHelper.COLUMN_NAME, nameBox.getText().toString());
        cv.put(DatabaseHelper.COLUMN_YEAR, Integer.parseInt(yearBox.getText().toString()));


        if (userId > 0) {
            db.update(DatabaseHelper.TABLE, cv, DatabaseHelper.COLUMN_ID + "=" + userId, null);
        } else {
            db.insert(DatabaseHelper.TABLE, null, cv);
        }

        goHome();
    }
    public void delete(View view){
        db.delete(DatabaseHelper.TABLE, "_id = ?", new String[]{String.valueOf(userId)});
        goHome();
    }
    private void goHome(){
        
        db.close();
        
        Intent intent = new Intent(this, MainActivity.class);
        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
        startActivity(intent);
    }

    }

'