8

DISCLAIMER: this is a copy paste from an older stackoverflow post that isn't available anymore, but I have exaclty the same problem, so it seemed appropriate to repost it as it was never answered.

I have a stored procedure that will return 4 result sets (contacts, addresses, email, phones) which is populated into a dataset. I would like to use AutoMapper to populate a complex object.

public class Contact 
{
    public Guid ContactId { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public List<Address> Addresses { get; set; }
    public List<Phone> Phones { get; set; }
    public List<Email> Emails { get; set; }
}

public partial class Address:BaseClass
{
    public Guid ContactId { get; set; }
    public string Address1 { get; set; }
    public string Address2 { get; set; }
    public string Address3 { get; set; }
    public string City { get; set; }
    public string StateProvince { get; set; }
    public string PostalCode { get; set; }
    public string CountryCode { get; set; }   
}

public class Email
{
    public Guid EmailId { get; set; } 
    public Guid ContactId { get; set; } 
    public string EmailAddress { get; set; }
}

public class Phone
{
    public Guid PhoneId { get; set; } 
    public Guid ContactId { get; set; }         
    public string Number { get; set; } 
    public string Extension { get; set; }
}

I have a method that will get data and return a list of contact. After the DataSet is populate, I define the relationships between the tables.

I found many examples where you convert the DataSet (or table) to a reader using the CreateDataReader method and that is what I'm doing here. The method will in fact parse the first table into the object, but will not enumerate through the related tables.

public List<Contact> GetContacts()
{
    List<Contact> theList = null;

    // Get the data
    Database _db = DatabaseFactory.CreateDatabase();
    DataSet ds = db.ExecuteDataSet(CommandType.StoredProcedure, "GetContacts");

    //The dataset should contain 4 tables
    if (ds.Tables.Count == 4) 
    {    
        //Create the maps
        Mapper.CreateMap<IDataReader, Contact>(); // I think I'm missing something here
        Mapper.CreateMap<IDataReader, Address>();
        Mapper.CreateMap<IDataReader, Email>();
        Mapper.CreateMap<IDataReader, Phone>();

        //Define the relationships        
        ds.Relations.Add("ContactAddresses", ds.Tables[0].Columns["ContactId"], ds.Tables[1].Columns["ContactId"]);
        ds.Relations.Add("ContactEmails", ds.Tables[0].Columns["ContactId"], ds.Tables[2].Columns["ContactId"]);
        ds.Relations.Add("ContactPhones", ds.Tables[0].Columns["ContactId"], ds.Tables[3].Columns["ContactId"]);

        IDataReader dr = ds.CreateDataReader();
        theList = Mapper.Map<List<Contact>>(dr);    
    }

    return (theList);    
}

I feel as though I'm missing something in the mapping for the Contact object, but I just can't find a good example to follow.

If I manually populate the contact object and then pass is to my controller, it will properly load the ContactModel object using a direct mapping

public ActionResult Index()
{
    //From the ContactController
    Mapper.CreateMap<Contact, Models.ContactModel>();
    Mapper.CreateMap<Address, Models.AddressModel>();

    List<Models.ContactModel> theList = Mapper.Map<List<Contact>, List<Models.ContactModel>>(contacts);

    return View(theList);
}

Is what I want to do even possible?

4

2 回答 2

9

IDataReader 映射器非常简单，它可以从数据读取器中填充对象，并通过列名映射对象属性。它并非旨在创建具有关系等的复杂数据结构。

此外，DataSet.CreateDataReader 将产生一个多结果集数据读取器 - 即，读取器对于每个表将有很少的结果集，但它不会保留关系。

所以，为了得到你想要的，你需要为每个表创建阅读器，将每个阅读器映射到不同的集合，然后使用这些结果来创建最终的复杂对象。

在这里，我提供了一种简单的方法，但您可以疯狂地创建自定义解析器等来封装所有内容。

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using AutoMapper;
using NUnit.Framework;

namespace StackOverflowExample.Automapper
{
    public class Contact
    {
        public Guid ContactId { get; set; }
        public string Name { get; set; }
        public List<Address> Addresses { get; set; }
    }

    public partial class Address
    {
        public Guid AddressId { get; set; }
        public Guid ContactId { get; set; }
        public string StreetAddress { get; set; }
    }

    [TestFixture]
    public class DatasetRelations
    {
        [Test]
        public void RelationMappingTest()
        {
            //arrange
            var firstContactGuid = Guid.NewGuid();
            var secondContactGuid = Guid.NewGuid();

            var addressTable = new DataTable("Addresses");
            addressTable.Columns.Add("AddressId");
            addressTable.Columns.Add("ContactId");
            addressTable.Columns.Add("StreetAddress");
            addressTable.Rows.Add(Guid.NewGuid(), firstContactGuid, "c1 a1");
            addressTable.Rows.Add(Guid.NewGuid(), firstContactGuid, "c1 a2");
            addressTable.Rows.Add(Guid.NewGuid(), secondContactGuid, "c2 a1");

            var contactTable = new DataTable("Contacts");
            contactTable.Columns.Add("ContactId");
            contactTable.Columns.Add("Name");
            contactTable.Rows.Add(firstContactGuid, "contact1");
            contactTable.Rows.Add(secondContactGuid, "contact2");

            var dataSet = new DataSet();
            dataSet.Tables.Add(contactTable);
            dataSet.Tables.Add(addressTable);

            Mapper.CreateMap<IDataReader, Address>();
            Mapper.CreateMap<IDataReader, Contact>().ForMember(c=>c.Addresses, opt=>opt.Ignore());

            //act
            var addresses = GetDataFromDataTable<Address>(dataSet, "Addresses");
            var contacts = GetDataFromDataTable<Contact>(dataSet, "Contacts");
            foreach (var contact in contacts)
            {
                contact.Addresses = addresses.Where(a => a.ContactId == contact.ContactId).ToList();
            }
        }

        private IList<T> GetDataFromDataTable<T>(DataSet dataSet, string tableName)
        {
            var table = dataSet.Tables[tableName];
            using (var reader = dataSet.CreateDataReader(table))
            {
                return Mapper.Map<IList<T>>(reader).ToList();
            }
        }
    }
}
于 2013-05-28T18:34:36.310 回答
1

我参加聚会的时间非常晚，但以防万一这对其他人有帮助。

我所做的是使用Json.NET将我的数据集序列化为 JSON 字符串。

var datasetSerialized = JsonConvert.SerializeObject(dataset, Formatting.Indented);

在 Visual Studio 中调试时将 json 作为字符串查看并将其复制到剪贴板。

然后在 Visual Studio 中转到编辑 -> 选择性粘贴 -> 将 JSON 粘贴为类

然后，您将为每个具有关系的表创建一个 POCO。

最后，将 JSON 反序列化为在将 JSON 粘贴为类时创建的“RootObject”。

var rootObj = JsonConvert.DeserializeObject<RootObject>(datasetSerialized);
于 2017-11-01T16:17:34.023 回答