android-新手求助：安卓sql查找的函數，報錯Nullpointerexception

新手求助：安卓sql查找的函數，報錯Nullpointerexception

代碼如下
public User search(String username){
SQLiteDatabase sdb = helper.getReadableDatabase();
Cursor cursor =sdb.rawQuery("select * from user where username=?", new String[]{username});

if(cursor.moveToFirst()){

String uname=cursor.getString(cursor.getColumnIndex("username"));

String pword=cursor.getString(cursor.getColumnIndex("password"));

User user=new User(uname,pword);
return user;

}

cursor.close();

return null;

}

最佳回答：

cursor.moveToFirst()改為cursor.next() 記得應該是next()函數的樣子