在小巧玲珑的映射实体 [英] Mapping entity in Dapper

问题描述

我刚开始与小巧玲珑的工作，我似乎还没有找到的东西很简单，就像在我的数据库实体映射到一个表：

I've just started working with Dapper and I don't seem to find something very simple like mapping an entity to a table in my database:

我有一个存储过程：

CREATE PROCEDURE [dbo].GetUserById (@UserId int)
AS  
begin               
        SELECT UserId,LastName,FirstName,EmailAddress
        FROM users
        WHERE UserID = @UserId

end
go

然后一个实体：

Then an entity:

public class User
{
    public int Id { get; set; }
    public string LastName { get; set; }
    public string FirstName { get; set; }
    public string Email { get; set; }
}

和我的code短小精悍查询：

And a dapper query in my code:

int userid=1;
    User User = connection.Query<User>("#GetUserById", new {userid=userid}, commandType: CommandType.StoredProcedure).FirstOrDefault();

我的问题是：我怎样才能知道我的实体网友认为标识是用户ID对我的数据库

My question is: How can I tell my entity User that Id is Userid on my database?

在EF，我会做这样的事情：

In EF I would do something like this:

MapSingleType(c => new
            {
                UserId = c.Id,
                Firstname = c.Firstname,
                Lastname = c.Lastname,
                EmailAddress = c.Email
            }).ToTable("users");

如何能在上面短小精悍的实现？

How can the above be achieved in dapper?

推荐答案

小巧玲珑的故意不具有映射层;这是绝对最低，可以工作，并坦言覆盖了绝大多数的真​​实场景的过程中。不过，如果我理解正确的话，你不希望在TSQL别名，并且不希望任何直通属性 - 然后使用非通用查询 API

Dapper deliberately doesn't have a mapping layer; it is the absolute minimum that can work, and frankly covers the majority of real scenarios in the process. However, if I understand correctly that you don't want to alias in the TSQL, and don't want any pass-thru properties - then use the non-generic Query API:

User user = connection.Query("...", ...).Select(obj => new User {
           Id = (int) obj.UserId,
           FirstName = (string) obj.FirstName,
           LastName = (string) obj.LastName,
           Email = (string) obj.EmailAddress
        }).FirstOrDefault();

或者更简单地在一个记录的情况下：

or perhaps more simply in the case of a single record:

var obj = connection.Query("...", ...).FirstOrDefault();
User user = new User {
      Id = (int) obj.UserId,
      FirstName = (string) obj.FirstName,
      LastName = (string) obj.LastName,
      Email = (string) obj.EmailAddress
};

这里的窍门是，非通用查询（...） API使用动态，提供高达每列名成员。

The trick here is that the non-generic Query(...) API uses dynamic, offering up members per column name.

这篇关于在小巧玲珑的映射实体的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！