entity-framework

Entitity Framework: Change tracking in SOA with POCO approach

In our layered application, we are accessing database via WCF calls. We are creating and disposing contexts per request. Also we are using POCO approach. My question is, in pure POCO model (completely persistent ignorant POCOs) is it possible to track the changes, while we are creating and disposing context per request (as previous conte...

Using Include() with inherited entities problem

In EF eager loading related entities is easy. But I'm having difficulties including inherited entities when loading data using table-per-type model. This is my model: Entities: ArticleBase (base article entity) ArticleSpecial (inherited from ArticleBase) UserBase (base user entity) UserSpecial (inherited from UserBase) Image R...

delete rows with entity framework

I have to delete all rows of a model with condition fkey_id = 1 What 's the better mode? thanks ...

entity framework nested conditions

Hi i have a model where i have to count the rows with conditions: uscitaservizio == false and accountid attribute (int) is in a string filtrodipe es: filtrodipe = "2,4,5,6" I' ve tried with this: db.TDP_Missioni.Count( p => p.UscitaServizio == false && (objUser.FiltroDipe != null ? (p.AccountID.ToString() in objU...

How do I prevent EntityDataSource to execute a query if controlparameters are invalid?

On an ASP.NET web page I have an EntityDataSource: <asp:EntityDataSource ID="EntityDataSourceOrders" runat="server" ConnectionString="name=EntitiesContext" DefaultContainerName="EntitiesContext" EntitySetName="Order" Select="it.OrderID,it.OrderCode,it.OrderDateTime" Where="it.OrderDateTime &gt;...

get attribute values from string key

Hi i need to obtain the value of attribute of a model by passing the name of attribute like string. ex model["ModelID"] is there any method for this? thanks ...

What is a way to do a Generic Repository with Entity Framework 4.0 where I have function imports? (I don't want just a generic "execute" function where I pass in strings for the function name and parameters)

I have a generic repository that I communicate with my object context with. My object context has function imports that I want to be able to call through my generic repository. Currently I call them through an "Execute" function, but this is not ideal because I have to pass in my function name and parameters as strings which can cause r...

How to tell what name RIA Services/EF Model uses for Associations?

Hi, I'm working on a C#.NET 3.5 WCF RIA Services app and having an issue with my Entity Framework model. My entity Foo is mapped to a DB table and has a primary key called FooId. My Bar is mapped to a DB view. I've selectively designed this view to generate a composite key in the EF using two of the columns (by making sure they were non...

Entity Framework - Is it possible to create a table containing strings of alternative names to generic types?

I have recently been trying to learn more about the Entity Framework technologies from Microsoft. I have found a situation which I am not sure if it is possible (or correct) to solve using EF. I have lots of entities that can be referred to by lots of different names. For example, a persons occupation maybe described as "Coder", "Progra...

Can I get a POCO from EF4's function import?

In the context of Entity Framework 4, the default behavior when adding a function import is to call it via ExecuteFunction<T>(), where T must apparently implement some property change notification stuff. (In my case it's generating a complex type derived from ComplexObject.) I don't need or want any change notifications, and I'm requir...

How do LINQ queries against the Entity Framework communicate dates to a SQL Server?

I'm using two LINQ queries to access my database using Entity Framework: The first stores a token in the database and gives it a 60 second timeout: string tokenHash = GetTokenHash(); Token token = new Token() { Client = client, Expiry = DateTime.Now.AddSeconds(60), UserId = userId, TokenHash = tokenHash, }; context.AddT...

Linq to Entities : relationship * - *

Hello, I have on my EF Schema a relationship * - * (designed by a middle table with 2 keys). When I want filter on each (ie : I want all market segment filtered by one function), I execute this query : var requete = from mkt in ent.MARKETSEGMENT_MKT where mkt.FUNCTION2_FUN.Where(fu => fu.FUN_ID == FunId).FirstOrDefault().FUN_ID == Fu...

Which shortcomings of Entity Framework have been addressed in .Net 4.0?

I'm committed to EF as I'm currently using it in a project but I also find it a major pain and learning curve as there are some things it does not do well that I would expect it to. Does anyone know if the following issues are any easier in EF 4.0? Foreign key access, sometimes you want the foreign key from a table rather than an enti...

Using Entity Framework how do I filter by a foreign key using multiple enumeration values?

Two tables (MainTable and EventType). EventType is represented in code as an enumeration and is foreign keyed in the database so that it looks like; Public enum EventTypeId As Integer Blah = 1 Blurgh = 2 Whoo = 3 End Enum I can run the following query fine; From M in dbx.MainTable Where M.EventType.EventTypeId = 1 But I...

Mapping between multiple tables in MVC

I have develop an application in MVC. I have 4 tables in MYSQL database. Topic(topicid,topic) with topicid as primary key subtopic(subtopicid,subtopic)with subtopicid as primary key question(questionid,question,answer) with question as primary key Detail(Id,topicid,subtopicid,questionid,title); with Id as primary key I have u...

How to have a read-only, not null field in an Entity Framework class

I have my Entity Framework model setup with a Sql Server 2008 backend. In the database, every table has a "CreatedBy" and "CreatedDate" field. These values are assigned when the object is saved, either by the Entity Context, or by Sql Server. In Sql Server, these fields are marked as "not null". I want these fields to be available...

Entity framework update existing entity without ASP.NETMVC TryUpdateModel

Hello, I'm new to EF and I've been using the asp.net mvc databind method to update my models "tryupdatemodel", now I have to update a entity from a service layer, since TryUpdateModel is a asp.net mvc method I can't use it in the services layer. What I need to do to update the data of an entity without using this method? I'm using repo...

How to use a JOIN in a LINQ query

I have the following table structure, which is imported into an Entity Framework project: (NOTE: I mislabled T1Name as T2Name in Table1) I have labeled the Entity Objects. The many-to-many joint table Table5, is represented as an EntityCollection<Entity4> in Entity3, and as an EntityCollection<Entity3> in Entity4 (EntityCollection<T>...

Are Complex Types in Entity Framework actually inheritance ?

Hi, I am learning EF and came across the definition of a Complex Type: "...used to define common properties among various entities." This sounds exactly like factoring out shared state from a class and moving it into a base class. My question is - is this inheritance from EF's perspective ? I know that inheritance is supported in E...

Converting String to Long ...in LINQ to Entity Framework using a MySQL adaptor.

I have a table with a column of type varchar where the majority of rows have numerical looking values, that is, each string contains nothing but the digits 0 through 9. +------+ | n | +------+ | 123 | | 234 | | BLAH | -- This row is an exception to the rule. | 456 | | 789 | +------+ In MySQL, this works: SELECT * FROM t WHERE n...