entity-framework-4

问题 This is my first time attempting full usage of mysql in .NET with MVC3, using code first technology. I have installed VS2010 (10.0.3), and MVC3, .NET 4 via web platform. I then installed MySQL .NET connector 6.4.3 . I then proceeded to setup a Data Connection in Server Explorer, and that seems to work fine. I configured the site using MySQL Website Configuration, and you can see the config settings below in the web.config. Then using Scott Hanselman's vid tutorial (http://www.asp.net/mvc

问题 I am using the Entity Framework 4.1 with POCO entities in a new project. Everything was working fine until I began caching the entities using AppFabric Caching. I started getting erros retrieving the entitis from the cache related to deserializing the proxy objects. I fixed this problem by setting ContextOptions.ProxyCreationEnabled = false. The issue now is when I get entities back from the cache, I have to attach the entity to the current context using ObjectSet.Attach(entity) and add them

问题 How can I update an entity without having to make a call to select it. If I supply the key for the entity, should it not know to update after SaveChanges() is called on the ObjectContext. I currently do this: var user = context.Users.Single(u => u.Id == 2); user.Username = "user.name"; user.Name = "ABC 123"; context.SaveChanges(); That works, but forces a select. Because I know the Id , why can't I do something like this: var user = new User(); user.Id = 2; user.Username = "user.name"; user

问题 I searched a bit and understands that I can use projection to partially load an entity , the question becomes is there a way to partially eager loading a child? Say I have the following Entity A has Id Name EntityB and Entity B has Id StuffToBeLoaded1 StuffToBeLoaded2 OtherStuffNotToBeLoaded How can I load A with B , and B only has stuffToBeLoaded1 and stuffToBeLoaded2? I guess I cannot call .Inlucde("EntityB") otherwise it is fully loaded, is it? 回答1: You must use custom query with a

问题 Is it possible to have such a scenario? Entity Framework 4 POCO entities in different assemblies with associations between them (that span multiple assemblies) ? 回答1: As I see it now, without making something that loads entities from the other assemblies in that unit of work, the scenario is not possible. 来源： https://stackoverflow.com/questions/4783716/entity-framework-4-with-poco-entities-in-different-assemblies-with-associations

问题 OK, here we go, after reading a couple of related questions, I haven't ended into a real productive solution for my thoughts. Thoughts: As we all developers creating applications, then these apps going into production, the client after couple of days demands additional features. Great! you open your database through Server Explorer, create tables, add columns, maybe changing datatypes and then updating your model from database, nice it works everything OK! Now you release the project with

问题 When working with an EF4 (edmx) model, we frequently need to process an "Update Model From Database". Commonly, we need to just delete table(s) and let them fully regenerate from the database. The issue at hand is that we have multiple recursive relationships/properties. By default, the "update Model From Database" process creates the property with the object's name and then adds a 1, 2, 3, etc. for each additional relationship. So if I have a table of "companies" where it points to itself

问题 I want to develop on sql server database and use MySql for production. I've created my database using SSMS Diagram and generated ADO.NET Enity Model in my ASP.NET MVC project. Then I modified connection string from Sql Server to point to MySql Server and specifically passed MySqlConnection object to DbContext. Now I'm trying to execute this below code but it complains that provided underlying connection is not of .NET Sql Server Connection type. dbContext.CreateDatabase(); 回答1: In the web

问题 I have a table Travelers : CREATE TABLE [dbo].[Travelers]( [TravelerId] [int] IDENTITY(1,1) NOT NULL, [FirstName] [nvarchar](25) NULL, [LastName] [nvarchar](50) NULL a table Transporters and a join table TransporterTravelers CREATE TABLE [dbo].[TransporterTravelers]( [Transporter_TransporterId] [int] NOT NULL, [Traveler_TravelerId] [int] NOT NULL, to create a many-to-many relationship between travelers and transporters. I used POCO classes to create the entities Traveler and Transporter, and

问题 Is it possible to have an entity model created out of two databases, with all the relationships between tables reflected in the model? How do you do that? I am referring to ADO.NET Entity Framework version 4. 回答1: Maybe. It depends on several factors. If using a modern version of SQL Server, there is a feature called Synonyms, which allows you to "map" a table from one database into another. Unfortunately, the EF Data designer doesn't recognize or understand Synonyms. There is a way to