Entity Framework Core - Knowledge Base (KB)

DateTime or int to string inside IQueryable?

How do I convert DateTime or int to string inside IQueryable? I need to do something like this, but without ...ToString()..., which throws ...System.NotSupportedException... exception:...IQueryable filteredEntities = myIQueryableCollection .Where(o =>...

Entity framework : Return grouped by value and sum of some columns in the same query

I have one table and I want to do the following in entity frame work :...1- Return some columns from the object not all columns ( I created new class for this new type contain only the columns I need and return values in it in select statement....2- Retur...

EF Combine several tables into one IQueryable

I'm using OData (WebAPI and EF) to query a database. And now I have to "...merge..." three tables into one result....I have 3 tables and an interface, which looks like this:...public class Authority : IAssociationEntity { public string Name { get; set...

Include not working after SelectMany + Select in Entity Framework Core

I have this query using Entity Framework Core (v2), but the ...Include.../...ThenInclude... don't work as I expected. This is the query:... var titlesOwnedByUser = context.Users .Where(u => u.UserId == userId) .Select...

Entityframework 6.2.0 IQueryable.Count VS IQueryable.ToList().Count

This is a very weird problem In short...var q = (some query).Count(); ...Gives my a number and...var q = (some query).ToList().Count(); ...Gives me entirely different number......with mentioning that (some query) has two includes (joins)...is there a sane...

EF Core conditional (add) includes to an IQueryable

In EF6 I was used to doing this:...var orders = GetAllEntities().Include(x => x.Contact.User); if (includeProducts) { orders = orders.Include(x => x.ProductOrders.Select(y => y.RentStockOrders)); orders = orders.Include(x => x.ProductOrders.Select...

IQueryable<T> to return a single record

I am using EF Core and am attempting to create a query provider which accepts any type and a single value. I then want to run a query to return the ...FirstOrDefault... of the passed in items which have the selected property set to the passed in value. so...

Unable to get complete SQL text from Entity Framework Core queries containing Union

I want to save the sql generated by entity framework/LINQ queries for documentation purposes. I had been using the IQueryable extension method from this blog post to get at the raw sql: ...http://rion.io/2016/10/19/accessing-entity-framework-core-queries-...

Why can't I filter an IQueryable like I can with a List?

I'm refactoring a project a little bit and have come back to a problem that I never got solved in the past. I am trying to perform multiple filters on a query of an EF Core db. ...In the past I had tried to setup a series of Where statements that did a ...

Group by hour in IQueryable

In my project I receive some data from an SPS all x seconds. Every y minutes I archive the current Data in a database so I'm able to show statistics. ...The data I receive gets put in a model. Something like this but much more complex:...public class Dat...

Create custom objects from IQueryable without loading everything into memory

This is a follow up question to ...this question.... You should read that first. ...I have now, thanks to ...this answer..., created a query that will return the correct entries. See:...IQueryable<Data> onePerHour = dataLastWeek .Where(d => ...

Set value of property in IQueryable<T> after join with another table based on some conditions

I am implementing Authorization for WPF. I have bound permissions with screens. For example, there is a screen called floor. It has four permissions associated with it....View Floor ...Add Floor...Edit Floor...Delete Floor...Along with every permission we...