轉換查詢對象使用LINQ to SQL

Question

我與LINQ工作在C＃SQL連接到SQL數據庫

，我對數據庫中的表稱爲Person持有有關人員的信息，並具有以下字段Person_Id ，First_Name，Last_Name，Email，Password

我已經返回一行以下查詢是否有匹配：

LINQDataContext data = new LINQDataContext(); 
      var query = from a in data.Persons 
         where a.Email == "Any Email String" 
         select a; 

我的問題是如何將query轉換爲它們定義等價類的一個實例是：

class Person 
{ 
    public int person_id; 
    public string First_Name; 
    public string Last_Name; 
    public string E_mail; 
    public string Password; 
    public Person() { } 
} 

Answer 1

像這樣：

Person query = (from a in data.Persons 
      where a.Email == "Any Email String" 
      select new Person { person_Id = a.Id, and so on }).FirstOrDefault(); 

Answer 2

我會做類似：

var query = (from a in data.Persons 
      where a.Email == "Unique Email String" 
      select new Person { person_Id = a.Id, etc etc }); 

//By using this code, you can add more conditions on query as well.. 

//Now the database hit will be made 
var person = query.FirstOrDefault();