Android 数据库查询报错

Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'android.database.Cursor android.database.sqlite.SQLiteDatabase.rawQuery(java.lang.String, java.lang.String[])' on a null object reference

        报错行代码：Cursor cursor = mSQLiteDatabase.rawQuery("select * from users",null);

mSQLiteDatabase需要声明定义一下

这句报错的翻译就是mSQLiteDatabase为null，检查

Cursor cursor = mSQLiteDatabase.rawQuery("select * from users",new String[0]);