entity-framework

Way to automate setting of MergeOptions

I am looking for an automated way to iterate over all ObjectQueries and set the merge option to no tracking (read only context). Once i find out how to do it i will be able to generate a default read only context using a T4 template. Is this possible? For example lets say i have these tables in my object context SampleContext Tab...

Entity Framework VS LINQ to SQL VS ADO.NET with stored procedures?

How would you rate each of them in terms of: Performance Speed of development Neat, intuitive, maintainable code Flexibility Overall I like my SQL and so have always been a die-hard fan of ADO.NET and stored procedures but I recently had a play with Linq to SQL and was blown away by how quickly I was writing out my DataAccess layer a...

Entity Framework associations killing performance

Here is the performance test i am looking at. I have 8 different entities that are table per type. Some of the entities contain over 100 thousand rows. This particular application does several recursive calculations on the client so I think it may be best to preload the data instead of lazy loading. If there are no associations I can...

Do I need to include all fields in my entity framework model

Quick question for everyone: Do I need to include all the database table fields on my EF model? For example; I've created a sub-model that only deals with tblPayment and associated tables. Now, I need to write a LINQ query to get some information about items. I would typically get this by joining tblPayment to tblInvoice to tblInvoic...

Entity Framework: Setting EntityReference EntityKey causes exception on save

I have a table with a ModifiedUserID field that is a foreign key to a User table. In entity framework, I'm loading the first table, but not the users table. I have the user ID of the current user, and would like to set the ModifiedUserID to that value for all entities that have been modified prior to saving. Before calling SaveChang...

convert a sql statement to class?

Is there a tool or code to convert a sql statement to class? Something like: Dim sqlText = "SELECT CustomerID, Name, Address, City FROM dbo.Customer WHERE CustomerID = 1" Dim obj As New ***SqlStatementTool***(sqlText) obj.GetTables() 'Will Return Tables in sqlText obj.GetWheres() 'Will Return conditions in sqltext obj.GetParameters() ...

2-Way databinding with Entity Framework and WPF DataGrid

I'm having trouble adding an Entity Framework entity to a ObjectContext's EntitySet automatically using the WPF 4.0 DataGrid's add functionality. Here's the setup: DataGrid-->BoundTo-->ListCollectionView-->BoundTo-->EntitySet When I interactively add a row to the DataGrid, the EntitySet does not have a new entity added to it. Updating ...

Map a property in the entity framework to a different type

I have a SQL Server 2008 database. I have a bunch of fields in TableA that are just strings that corresponds to booleans. So every value is either true or false. The edmx I generated using Entity Framework 4.0 has them as strings. This is technically correct but I would like to have them mapped as Booleans instead. Is this possible?...

Entity Framework foreign relationship issue

I've had an entity framework model working for some time. Yesterday, it suddenly started complaining about a foreign key relationship issue during an insert. I've checked the fields and can do a manual insert using the exact field values. But the EF continues to complain. Any ideas what could have happened? ...

Entity Framework Adding new record with foreign key constraint

In an effort to learn the entity framework I have created two tables in a one to many relationship. The one table (Author) has the following fields - AuthorID, FirstName, LastName. The many table (Payroll) has the following fields - PayrollID, AuthorID, Salary. I have CRUD stored procdures for insert, update and delete. What I am tyi...

Entity Framework query

Hi all, I have a piece of code that I don't know how to improve it. I have two entities: EntityP and EntityC. EntityP is the parent of EntityC. It is 1 to many relationship. EntityP has a property depending on a property of all its attached EntityC. I need to load a list of EntityP with the property set correctly. So I wrote a piece ...

Dump Linq-To-Sql now that Entity Framework 4.0 has been released?

The relative simplicity of Linq-To-Sql as well as all the criticism leveled at version 1 of Entity Framework (especially, the vote of no confidence) convinced me to go with Linq-To-Sql "for the time being". Now that EF 4.0 is out, I wonder if it's time to start migrating over to it. Questions: What are the pros and cons of EF 4.0 rela...

Entity Framework and WCf

Hi I am little confused on designing WCf services with EF. When using WCf and EF, where do we draw this line on what properties to return and what not to with the entity. Here is my scenario I have User. Here are the relations. User [1 to many] Address, User [ 1 to many] Email, User [ 1 to many] Phone So now on the webform, on pa...

Entity Framework 4.0 Databinding with sorting not working

I want to do something that I thought would be very simple. I want to bind a generated Entity Framework EntityCollection to a WPF DataGrid. I also want this grid to be sortable. I have tried all kinds of things to make this happen, including using a CollectionViewSource. However, nothing seems to work. Using a normal CollectionViewSourc...

EF4 - possible to mock ObjectContext for unit testing?

Can it be done without using TypeMock Islolator? I've found a few suggestions online such as passing in a metadata only connection string, however nothing I've come across besides TypeMock seems to truly allow for a mock ObjectContext that can be injected into services for unit testing. Do I plunk down the $$ for TypeMock, or are there a...

Display empty textbox using Html.TextBoxFor on a not-null property in an EF entity.

I am using Entity Framework (v4) entities. I have an entity called Car with a Year property of type integer. The Year property does not allow NULL. I have the following in my Create view: <%= Html.TextBoxFor(model => model.Year) %> I am required to return a new Car object (due to other requirements) in my HttpGet Create action in the ...

EntityFramework gives IDisposable error

I use EF for the back-end DataLayer in my asp.net websites. I create a class library and add the Model in it, reference it and use it from the ASP.NET Website. But this time, I generated the model from database but it seems does not implement IDisposable, and the methods I used to see are not there. DeleteObject , SaveChanges etc. There ...

How to assign default values and define unique keys in Entity Framework 4 Designer

Hello, I've had a look at the Entity Framework 4. While generating code for the SQL Server 2008 I came to the point where I want to define some default values for some fields. how to define in the designer for a Created DateTime Field the DateTime.Now default value? -> Error 54: Default value (DateTime.Now) is not valid for DateTime...

How to reference using Entity Framework and Asp.Net Mvc 2

Tables CREATE TABLE [dbo].[Users]( [UserId] [int] IDENTITY(1,1) NOT NULL, [UserName] [varchar](50) COLLATE SQL_Latin1_General_CP1_CI_AS NULL, [Email] [varchar](255) COLLATE SQL_Latin1_General_CP1_CI_AS NULL, [BirthDate] [smalldatetime] NULL, [CountryId] [int] NULL, CONSTRAINT [PK_Users] PRIMARY KEY CLUSTERED ([UserId] ASC )WITH (PAD_IN...

EF - Entity Sql contains clausule with string

Hi all, I have one question about EF. If I understand correctly EF does not support Contains. I try to achieve this: I have column(nvarchar) with this: for ex.row1. 1;3;4;5,row2. 3;4;6 row3. 7;8;16 etc. I have list(of string) with 1,6. My goal is to get row1 and row2 in result set. I try with linq to entity and with linq to sql but i can...