关于android数据库查询操作的问题

public User find(int id)
{
db = helper.getWritableDatabase();
Cursor cursor = db.rawQuery("select mima from userdb where id =?", new String[]
{ String.valueOf(id) });
if (cursor.moveToNext())
{
return new User(cursor.getString(cursor.getColumnIndex("mima"));//这行有错误
}
return null;
}
错误提示：
Multiple markers at this line
- The constructor User(String) is
undefined
我是模仿这段代码写的，本人初学者，求大神指教

public Student find(int sid)
{
db = helper.getWritableDatabase();
Cursor cursor = db.rawQuery("select sid,name,age from t_student where sid = ?", new String[]
{ String.valueOf(sid) });
if (cursor.moveToNext())
{
return new Student(cursor.getInt(cursor.getColumnIndex("sid")), cursor.getString(
cursor.getColumnIndex("name")), cursor.getShort(cursor.getColumnIndex("age")));
}
return null;
}

错误提示是：he constructor User(String) is undefined，刚刚的忘了加一个括号

new User(cursor.getString(cursor.getColumnIndex("mima")));最右边少了个括号吧

不要用query方法，直接用sql语句查询 select * from notes where _id = "10"