Типы API-интерфейсов OData V4 для Web API - Как настроить Контекст контроллера и данных

Ответ 1

Теперь я не использую Entity Framework после его ошибки с кэшированием данных. Посмотрите на Fluent NHibernate. В нем ORM вы можете настроить сопоставление динамических свойств OData v4 с типом пользователя. Используйте пакет nuget Newtonsoft.Json.

Ваш класс:

public class Item
{
    [Key]
    public Guid ItemId { get; set; }

    // dynamic properties for the open type
    public IDictionary<string, object> DynamicProperties { get; set; }

    ... 
}

и StoreDynamicProperties для класса Fluent NHibernate:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.Common;
using Newtonsoft.Json;
using NHibernate.UserTypes;
using NHibernate.SqlTypes;

[Serializable]
public class StoreDynamicProperties : IUserType
{
    private JsonSerializerSettings _settings = new JsonSerializerSettings(); // { TypeNameHandling = TypeNameHandling.All };

    public new bool Equals(object x, object y)
    {
        if (x == null && y == null)
            return true;

        if (x == null || y == null)
            return false;

        var xdocX = JsonConvert.SerializeObject((IDictionary<string, object>)x, _settings);
        var xdocY = JsonConvert.SerializeObject((IDictionary<string, object>)y, _settings);

        return xdocY == xdocX;
    }

    public int GetHashCode(object x)
    {
        if (x == null)
            return 0;

        return x.GetHashCode();
    }

    public object NullSafeGet(IDataReader rs, string[] names, object owner)
    {
        if (names.Length != 1)
            throw new InvalidOperationException("Only expecting one column…");

        var val = rs[names[0]] as string;

        if (val != null && !string.IsNullOrWhiteSpace(val))
        {
            return JsonConvert.DeserializeObject<IDictionary<string, object>>(val, _settings);
        }

        return null;
    }

    public void NullSafeSet(IDbCommand cmd, object value, int index)
    {
        var parameter = (DbParameter)cmd.Parameters[index];

        if (value == null)
        {
            parameter.Value = DBNull.Value;
        }
        else
        {
            parameter.Value = JsonConvert.SerializeObject((IDictionary<string, object>)value, _settings);
        }
    }

    public object DeepCopy(object value)
    {
        if (value == null)
            return null;

        //Serialized and Deserialized using json.net so that I don't
        //have to mark the class as serializable. Most likely slower
        //but only done for convenience. 

        var serialized = JsonConvert.SerializeObject((IDictionary<string, object>)value, _settings);

        return JsonConvert.DeserializeObject<IDictionary<string, object>>(serialized, _settings);
    }

    public object Replace(object original, object target, object owner)
    {
        return original;
    }

    public object Assemble(object cached, object owner)
    {
        var str = cached as string;

        if (string.IsNullOrWhiteSpace(str))
            return null;

        return JsonConvert.DeserializeObject<IDictionary<string, object>>(str, _settings);
    }

    public object Disassemble(object value)
    {
        if (value == null)
            return null;

        return JsonConvert.SerializeObject((IDictionary<string, object>)value);
    }

    public SqlType[] SqlTypes
    {
        get
        {
            return new SqlType[] { new StringSqlType(8000) };
        }
    }

    public Type ReturnedType
    {
        get { return typeof(IDictionary<string, object>); }
    }

    public bool IsMutable
    {
        get { return true; }
    }
}

и в классе ItemMap:

using FluentNHibernate.Mapping;

public class ItemMap : ClassMap<Item>
{
    public ItemMap()
    {
        Table("Items");

        Id(item => item.ItemId)
            .GeneratedBy
            .GuidComb();

        Map(item => item.DynamicProperties)
            .CustomType<StoreDynamicProperties>()
            .Column("Properties")
            .CustomSqlType("varchar(8000)")
            .Length(8000);
        ...
    }
}