EF 4.3和CodeFirst：一对多导航属性在没有实体代理的情况下加载为空值

Question

Problem is next - i have 2 entities with one-to-many relationships:

public class Schema
{
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public Guid SchemaId { get; set; }

    public string Name { get; set; }

    public string Content { get; set; }

    public string ElementName { get; set; }

    public List<Element> Elements { get; set; }
}

public class Element
{
    [DatabaseGenerated(DatabaseGeneratedOption.None)]
    public Guid ElementId { get; set; }

    public Guid SchemaId { get; set; }

    public string Content { get; set; }

    public Schema InSchema { get; set; }
}

and project referenced to EntityFramework v4.3 package. After storing some Schemas with related Elements in database I load Schemas list (for example, var schemasList=context.Schemas.ToList()). After this in all instances of Schema in Elements property values is null. Now i solve this problem with adding dynamic proxy for entities, but this have some bad impact in numerous dev scenarious (eg saving may cause "Entity tracking by multiple context" error). Thank for any help with this problem.

Answer 1

Have you used .Include in your query?

ie

from s in Schema.Include(sc=>sc.Elements)
select s;

note you will need

using System.Data.Entity 

to use include