To fix this use a temporary variable: var tmp = aa[i]; … m => m.PresId == tmp In your where clause you have m => m.PresId == aa[i] which is a way of expressing a lambda expression. When that is converted to an expression, then converted into a query on your database it finds the … Read more
The accepted answer is better in this case, but for reference you can use the EntityFunctions class to perform operations on dates, among other things. where (vid.CreatedDate >= EntityFunctions.AddDays(DateTime.Now, -maxAgeInDay))
Let me preface this by saying that I am a dyed-in-the-wool database guy. As a gross over-generalization: Developers don’t know SQL. Developers don’t really want to know SQL. They can write it, they can design tables, but it makes them feel icky. They tend to do stupid things when the necessary query is more than … Read more
I found the answer. Of course, it is possible to convert DbSet in Entity framework to ObjectQuery using the below lines of code. ObjectContext objectContext = ((IObjectContextAdapter)db).ObjectContext; ObjectSet<Request> objectSet = objectContext.CreateObjectSet<Request>(“Requests”); where, db – Context class inherting from DbContext. Requests – DbSet<Request> defined in Context class. objectSet – Can now be passed as ObjectQuery.
I don’t think EF supports a translation for a String to DateTime or vice-versa conversion. As I see it, you have two options, depending on the format of the date in the string field: If the format is fairly simple, a string comparison might be enough: // Convert the boundaries to strings first // TODO: … Read more
http://social.msdn.microsoft.com/Forums/en-US/adodotnetentityframework/thread/6529a35b-6629-44fb-8ea4-3a44d232d6b9/ var people = entities.People.Where(“it.Name LIKE @searchTerm”, new ObjectParameter(“searchTerm”, searchTerm));
Update: If you are using Entity Framework Core you should use the following syntax var hierarchy = from p in ctx.Parents .Include(p => p.Children) .ThenInclude(c => c.GrandChild) select p;
That is definitely not the case. LINQ-to-Objects is a set of extension methods on IEnumerable<T> that allow you to perform in-memory query operations on arbitrary sequences of objects. The methods accept simple delegates when necessary. LINQ-to-Entities is a LINQ provider that has a set of extension methods on IQueryable<T>. The methods build up an expression … Read more
Ok, I think I understand the question – the gist of it is you want to be able to call a SQL UDF as part of your Linq to Entities query. This is if you’re using database or model first: This article explains how to do it: http://msdn.microsoft.com/en-us/library/dd456847(VS.100).aspx To sum it up, you first need … Read more
You’re probably looking for something like Predicate Builder which allows you to control the AND’s and OR’s of the where statement easier. There’s also Dynamic Linq which allows you to submit the WHERE clause like a SQL string and it will parse it into the correct predicate for a WHERE.