ASP.NET EF - DbContext的DbSet未被更新

Question

I am having a problem, my DbContext is not updating the items inside my DbSet for some specific cases.

I have two projects, a Backend (where is the .mdf file and connection string file) and WCF Service Project (where is a link (add existing item) to .mdf and connection string file).

In my Backend Project I have the following:

namespace BackEnd
{
    public static class CategoryEngine
    {
        public static void InsertCategory(string categoryName, string categoryDescription)
        {
            using (var db = new DiamondsDbContext())
            {
                db.CategorySet.Add(new Category { Name = categoryName, Description = categoryDescription });
                db.SaveChanges();
                db.Dispose();
            }
        }

        public static List<Category> SelectCategory()
        {
            using (var db = new DiamondsDbContext())
            {
                return db.CategorySet.ToList();
            }
        }
}


namespace BackEnd.DAL
{

    public class DiamondsDbContext : DbContext
    {
        public DiamondsDbContext()
            : base("DefaultConnection")
        {
        }

        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            modelBuilder.Conventions.Remove<PluralizingTableNameConvention>();
        }

        public DbSet<Category> CategorySet { get; set; }
    }
}

In my WCF Service Project :

namespace API
{
    [ServiceBehavior(IncludeExceptionDetailInFaults = true)]
    public class Diamond : IDiamond
    {
        public List<Category> SelectCategory()
        {
            return CategoryEngine.SelectCategory();
        }

        public void InsertCategory(Category category)
        {
            CategoryEngine.InsertCategory(category.Name, category.Description);
        }
}
}

Working Scenarios:

• I open my view in Backend ASP Web Project (Insert/Select) methods working fine every time.

Not Working Scenarios:

DbSet has initially 4 items

• I Open my http://localhost:8080/diamond/category shows 4 items (OK)
• I Open my view in Backend ASP stills shows 4 items (OK)
• I add one item from my Backend ASP shows 5 items (OK)
• I open again my http://localhost:8080/diamond/category shows still 4 items (NOT OK)

My web.config file in Backend Project:

<configuration>  
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings configSource="ConnectionString.config">
  </connectionStrings>
  <!-- more stuff not related with the issue -->
</configuration>

My web.config file in WCF Service Project:

<configuration>
  <configSections>
    <section name="entityFramework" type="System.Data.Entity.Internal.ConfigFile.EntityFrameworkSection, EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" requirePermission="false" />
  </configSections>
  <connectionStrings configSource="ConnectionString.config">
  </connectionStrings>
</configuration>

My ConnectionString.config file existing in Backend project and linked in WCF Service Project:

<connectionStrings>
  <!--<add name="DefaultConnection" connectionString="Data Source=(LocalDb)\MSSQLLocalDB;Integrated Security=True" providerName="System.Data.SqlClient" />-->
  <!--<add name="DefaultConnection" connectionString="Server=(localdb)\diamonds4;Integrated Security=true" providerName="System.Data.SqlClient" />-->
  <add name="DefaultConnection" connectionString="Data Source=(localdb)\teste123;AttachDbFilename=|DataDirectory|77Diamonds.mdf;Integrated Security=True" providerName="System.Data.SqlClient" />
</connectionStrings>

Solution Image maybe it helps:

Answer 1

你不需要指定“db.Dispose（）;”

Answer 2

I was thinking, maybe my WCF Service is caching the GET requests? and sending always the same response? How can I be sure of this?

Check here my WCF Rest Interface implementation:

namespace API
{
    [ServiceContract]
    public interface IDiamond
    {
        [OperationContract]
        [WebInvoke(Method = "GET",
                    ResponseFormat = WebMessageFormat.Json,
                    BodyStyle = WebMessageBodyStyle.Bare,
                    UriTemplate = "category")]
        List<Category> SelectCategory();
    }
}