Entities as Linq: Counting takes a long time.

Linq to Entities vs. Linq to SQL vs. Entity Framework

I've seen several articles on using a database in a WPF.Net 4 application. I believe the primary two technologies are:...SQL with Linq (L2S)...Enterprise Framework (EF)...I sometimes see mention of the Linq to Entities (L2E) technology, but I can never figure out what makes L2E different from EF....So, my question is: Are there any differences betw...

The LINQ expression node type 'Invoke' is not supported in the entity framework's LINQ to Entities.

Can somebody assist me in resolving my problem? I'm use the code below:...public IEnumerable<InvoiceHeader> Getdata(Expression<Func<InvoiceHeader, bool>> predicate) { return AccountsContext.InvoiceHeaders.Include("Company").Include("Currency") .Include("BusinessPartnerRoleList").Include("DocumentType") .Where(predicate); } .....

LINQ + Entity Framework + "Contains" == Slow as molasses?

One of the dangers of postponed execution in Linq is this: When you first try...StudentIds... actually an...IQueryable... not a collection stored in memory. It will thus execute the second query on the database once again each time it is used....forcing the initial query's execution using...ToArray()... makes ...StudentIds... a memory collection, ...

LINQ-To-Entity (LINQ to Entities does not support the given type member ".)

I'm having trouble comprehending this issue:...Here is the T-SQL query I must use LINQ to Entities to implement....select r.ReviewID, b.BusinessID, b.Name as BusinessName ,r.Description from gb_business.Review r inner join gb_business.Business b on r.BusinessID = b.BusinessID inner join gb_listing.RegionalService rs on b.BusinessID = rs.BusinessID ...

In System.Data.Entity.dll (Entity Framework), why am I receiving a NullReferenceException?

Make a comprehensive check of the database if it just affects Nevada in order to rule out a data issue....In conclusion, the main issue was:...Db-first was used.......was supplying a null value for a field that was designated as non null in EF.

LINQ to Entities group by and Count()

What I have is this using LINQ-to-Entities...from r in ctx.Rs join p in ctx.Ps on r.RK equals p.RK group r by r.QK into gr select new { QK = (int)gr.Key, Num = gr.Count() } ...it contradicts this framework...Table P Table R Table Q PK* RK ----> RK* Text QK ------> QK* Text Text ...and sends the following message if any ent...

Error on Cout but i am not using Count in my LINQ exrpression,

Although I don't have much experience with EF, I did find a ...outdated MSDN article... where the same fault was mentioned. They were inside doing a computation.....Skip()... and to correct it, they carried out the computation independently and just used the output in their LINQ expression....Try to calculate....page * rows... Initially, use that o...

Getting COUNT and SKIP TAKE in one operation with Linq to Entities

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Entity Framework bulk inserts - creating a large number of objects / entities is the slow part?

The Detect Changes area of your "building all the items" section is the time-consuming component....Always choose AddRange over Add....Addition: Track modifications for each object....AddRange: Only ever detect changes (after all object are added)...This code should speed up the object creation process:...DataTable ref1 = ConvertCSVtoDataTable(csv,...

Entity Framework Count with a filter on field really slow - large count

One firm has a lot of members while I am doing a Model Mapping, like 405,000 members....viewModel.EmployeeCount = company.MembershipUser.Count(x => x.Deleted == false); ...The SQL query takes a few milliseconds to execute when I run it. One list view controller hit may take up to ten minutes in ASP.NET MVC using EF6 C#. Thoughts?...MembershipUser i...