将行拆分为多个嵌套对象

Question

我有以下查询：

select id, name, email, supervisor, createdBy, createdAt, changedBy, changedAt from XXX

现在，我想将每一行映射到如下所示的内容中：

public class Organisation{
  public int Id{get; set; }
  public string Name{get; set; }
  public ContactInfo Contact{get;set;}
  public Action CreatedBy{get;set;}
  public Action ChangedBy{get;set;}
}
public class ContactInfo{
  public string Name{get;set;}
  public string Email{get;set;}
}
public class Action{
  public string Username{get;set;}
  public DateTime At{get;set;}
}

我看过一些展示如何对信息进行分区的示例，但在这个示例中似乎行不通。可以完成还是应该将我的查询映射到一个辅助对象，然后将其映射到这些类?

谢谢。

路易斯

Answer 1

Dapper allows you to map a single row to multiple objects. This is a key feature if you want to avoid extraneous querying and eager load associations.

您可以阅读更多内容here

下面是一个例子：

[Test]
public void Test_Multi()
{
    using (var conn = new SqlConnection(@"Data Source=.\sqlexpress;Integrated Security=true; Initial Catalog=foo"))
    {
        var result = conn.Query<Organisation, ContactInfo, Action, Action, Organisation>(
            @"select Id = 100, Name = 'Foo', 
                Name = 'Contact Name', Email = 'contact@foo.com', 
                Username = 'The Creator', At = '12/25/2017', 
                Username = 'The Modifier', At = '12/26/2017' ",
            (org, contact, cretedBy, changedBy) =>
            {
                org.Contact = contact;
                org.CreatedBy = cretedBy;
                org.ChangedBy = changedBy;

                return org;
            }, splitOn: "Id, Name, Username, Username").First();

        Assert.That(result.Id, Is.EqualTo(100));
        Assert.That(result.Contact.Email, Is.EqualTo("contact@foo.com"));
        Assert.That(result.CreatedBy.Username, Is.EqualTo("The Creator"));
        Assert.That(result.ChangedBy.Username, Is.EqualTo("The Modifier"));

    }
}

将行拆分为多个嵌套对象

Splitting row into several nested objects

dapper