Android数据库报错

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

db对象为空，看看你前面的代码呢，调试一下，看哪一步拿到的db是空值