如何实现只读的ContentProvider？

public class MyContentProvider extends ContentProvider {
    private SQLiteDatabase database;

    @Override
    public boolean onCreate() {
        // 初始化操作，创建数据库连接等
        database = SQLiteDatabase.openOrCreateDatabase(getContext().getFilesDir().getPath() + "/mydata.db", null);
        return true;
    }

    @Override
    public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
        // 处理查询请求并返回只读的数据
        Cursor cursor = database.query("mytable", projection, selection, selectionArgs, null, null, sortOrder);
        return cursor;
    }

    @Override
    public String getType(Uri uri) {
        // 返回数据的MIME类型
        return "vnd.android.cursor.dir/mytable";
    }

    // 其他方法省略...

}

<provider
    android:name=".MyContentProvider"
    android:authorities="com.example.myapp.provider"
    android:exported="true" />