Entity Framework 6 - Knowledge Base (KB)
5242 results for: in tag: entity-framework
Entity Framework vs LINQ to SQL
Now that .NET v3.5 SP1 has been released (along with VS2008 SP1), we now have access to the .NET entity framework....My question is this. When trying to decide between using the Entity Framework and LINQ to SQL as an ORM, what's the difference?...The way...
asked by Chris Roberts
Expression.Invoke in Entity Framework?
The Entity Framework does not support the ...Expression.Invoke... operator. You receive the following exception when trying to use it:..."The LINQ expression node type 'Invoke' is not supported in LINQ to Entities....Has anyone got a workaround for this ...
asked by Brad Leach
Update database schema in Entity Framework
I installed VS SP1 and played around with Entity Framework....I created a schema from an existing database and tried some basic operations....Most of it went well, except the database schema update....I changed the database in every basic way:...added a n...
asked by Biri
ADO.NET Entity Framework tutorials
Does anyone know of any good tutorials on ADO.NET Entity Framework?...There are a few useful links here at ...Stack OverFlow..., and I've found one tutorial at ...Jason's DotNet Architecture Blog..., but can anyone recommend any other good tutorials? Any...
asked by Yngvar Johnsen
Using MySQL with Entity Framework
Can't find anything relevant about Entity Framework/MySQL on Google so I'm hoping someone knows about it.
asked by vintana
Can you use Microsoft Entity Framework with Oracle?
Is it possible to use Microsoft Entity Framework with Oracle database?
asked by Xerx
ADO.NET Entity Framework and identity columns
Is the Entity Framework aware of identity columns? ...I am using SQL Server 2005 Express Edition and have several tables where the primary key is an identity column. when I use these tables to create an entity model and use the model in conjunction with a...
asked by matthew thomas
How to relate objects from multiple contexts using the Entity Framework
I am ...very... new to the entity framework, so please bear with me......How can I relate two objects from different contexts together?...The example below throws the following exception:...System.InvalidOperationException: The relationship between the ...
asked by Giovanni Galbo
What are the alternatives to using Expand in a LINQ to ADO.net Data Service Query?
I am wondering if there are any alternatives to using the Expand key word when performing an LINQ to ADO.net Data Services query. The expand method does get me the data I am interested in, but it requires me to know all of the sub-objects that I am going...
asked by ChrisHDog
Entity Framework Validation
I'm getting ready to start a new project and I've been researching the entity framework. My question is what is the best strategy for validating the entities? Other projects I've worked on have used attributes for most of the validation, but obviously thi...
asked by Micah
How to create foreign key relationships with the Entity Framework?
I want to create a new row in my database on a table that has a couple of foreign key relationships and I haven't been able to get a handle on what order and what calls need to be made. This is what I have so far:...db.Models.Order order = DB.Models.Order...
asked by Jared
Using Entity Framework entities as business objects?
I'm using Entity Framework O/R mapper from Microsoft and using entity classes (generated classes that are mapped to DB objects) as a business objects. Is this OK? Please state your cons or pros. What to do in a case of WCF communication between business ...
asked by Aleksandar
How do I build a Linq Expression Tree that compares against a generic object?
I have an IQueryable and an object of type T....I want to do IQueryable().Where(o => o.GetProperty(fieldName) == objectOfTypeT.GetProperty(fieldName))...so ......public IQueryable<T> DoWork<T>(string fieldName) where T : EntityObject { ... T...
asked by JTew
Linq To Sql vs Entity Framework Performance
I have been searching for recent performance benchmarks that compare L2S and EF and couldnt find any that tested calling stored procedures using the released version of EF. So, I ran some of my own tests and found some interesting results....Do these resu...
asked by Vyrotek
How do I use a WPF TreeView HierarchicalDataTemplate with LINQ to Entities?
I've got a Page class in my .edmx ADO.NET Entity Data Model file with with Parent and Children properties. It's for a hierarchy of Pages....removed dead ImageShack link - ADO.NET Entity Framework Hierarchical Page Class...This is handled in my SQL databa...
asked by Zack Peterson
WPF TreeView Binding
I've got a class with Parent and Children properties....ADO.NET Entity Framework Hierarchical Page Class http://img148.imageshack.us/img148/6802/edmxxe8.gif...I want to display this hierarchy in a WPF treeview....Here's my XAML......<TreeView Margin="12" ...
asked by Zack Peterson
Logging every data change with Entity Framework
There is a need from a customer to log every data change to a logging table with the actual user who made the modification. The application is using one SQL user to access the database, but we need to log the "real" user id....We can do this in t-sql by w...
asked by Biri
How do I apply OrderBy on an IQueryable using a string column name within a generic extension method?
public static IQueryable<TResult> ApplySortFilter<T, TResult>(this IQueryable<T> query, string columnName) where T : EntityObject { var param = Expression.Parameter(typeof(T), "o"); var body = Expression.PropertyOrField(param,columnName); var sor...
asked by JTew
How do I get the max ID with Linq to Entity?
I have a table User which has an identity column ...UserID..., now what is the correct Linq to Entity line of code that would return me the max ...UserID...?...I've tried:...using (MyDBEntities db = new MyDBEntities()) { var User = db.Users.Last(); ...
asked by Ray
TDD and ADO.NET Entity Framework
I've been playing with ADO.NET Entity Framework lately, and I find that it suits my needs for a project I'm developing. I also find cool its non-invasive nature....After generating a data model from an existing database you are faced with the task of inte...
asked by Dario Solera
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