entity-framework-core

I've been going through my application, and there are times where only part of the IQueryable is actually translated into a SQL query and the rest of the work is done in-memory. I understand that there's no way for the EF team to account for every possible expression that a developer may come up with and magically translate that into a useable SQL query, but IIRC, EF would throw an exception if it was unable to translate ALL of the operations defined in an IQueryable to SQL. Is there a way to have EF Core also throw an exception, or at the very least, raise an event when it's unable to fully

Within ConfigureServices I have services.AddDbContext<MyContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))); as well as services.AddSingleton<IMyModel>(s => { var dbContext = s.GetService<MyContext>(); var lastItem= dbContext.Items.LastOrDefault(); return new MyModel(lastItem); }); But s.GetService<MyContext>() throws an error: Cannot resolve scoped service 'MyContext' from root provider. How can I achieve that? I don't want to inject MyDbContext in MyModel contructor as it is in a library which should have no reason to know about Entity Framework

I created an Inline Table-Valued Functions (ITVF) in SQL Server that returns a table of values (query simplified for discussion purposes): CREATE FUNCTION dbo.VehicleRepairStatus() RETURNS TABLE AS RETURN SELECT VehicleID, CurrentStatus FROM VehicleRepairHistory ... Which I can reference in a query: SELECT v.ID, v.Name, r.CurrentStatus FROM Vehicle v LEFT OUTER JOIN dbo.VehicleRepairStatus() r on v.ID = r.VehicleID I'd like to be able to use it in Linq query: var vehicles = await _databaseContext.Vehicles .Join() // join ITVF here? .Where(v => v.Type == 'Bus' ) .OrderBy(v => v.Name)

I use projection to map the Entity classes to DTOs using Entity Framework Core. However, projection adds ToList into child collection properties and this slows down the query a lot. Company Entity: public class Company { public Company() { Employees = new List<CompanyEmployee>(); } public string Address { get; set; } public virtual ICollection<CompanyEmployee> Employees { get; set; } ... } Company DTO: public class CompanyDTO { public CompanyDTO() { CompanyEmployees = new List<EmployeeDTO>(); } public string Address { get; set; } public List<EmployeeDTO> CompanyEmployees { get; set; } ... }

In Fluent Api at EF Core 2.0.0 , there aren't any methods HasRequired and HasOptional , and i have tow Models, Person and Employee: public class Person { public int Id { get; set; } public int EmployeeId { get; set; } public virtual Employee Employee { get; set; } // Optional } public class Employee { public int Id { get; set; } public int PersonId { get; set; } public virtual Person Person {get; set; } // Required } Person May to have Employee: Optional Employee Should have Person: Required How to apply these convetions in database. You could just specify int? as EmployeeId property type. BTW

Consider this aggregate root... class Contact { ICollection<ContactAddress> Addresses { get; set; } ICollection<ContactItem> Items { get; set; } ICollection<ContactEvent> Events { get; set; } } ...which I have used like so... class Person { Contact ContactDetails { get; set; } } How do I eager load all of the collections with the contact? I tried this... Context .Set<Person>() .Include(o => o.ContactDetails) .ThenInclude(o => o.Addresses) .ThenInclude(????) . ... I've also tried this... Context .Set<Business>() .Include(o => o.ContactDetails.Addresses) .Include(o => o.ContactDetails.Events)

I'm reading "Building Web Applications with Visual Studio 2017" (by Philip Japikse, Kevin Grossnicklaus, and Ben Dewey) and am getting stuck. When trying to create a class for a custome execution strategy with Entity Framework Core I get error CR0246 "The type or namespace name 'ExecutionStrategyContext' could not be found (are you missing a using directive or assembly reference?)" The text only states that only System and Microsoft.EntityFrameworkCore.Storage are required references. The EF Core 2.0 documentation seems to match the text but I cannot get the error to go away. Note: The book

Hi I have the same problem that an old post that is here, the solution offer there doesn't work for me in MVC 6 with EF7 is simple public class Match { [Key] public int MatchId { get; set; } public DateTime playday { get; set; } public float HomePoints { get; set; } public float GuestPoints { get; set; } public int HomeTeamId { get; set; } public int GuestTeamId { get; set; } [ForeignKey("HomeTeamId")] [InverseProperty("HomeMatches")] public virtual Team HomeTeam { get; set; } [ForeignKey("GuestTeamId")] [InverseProperty("AwayMatches")] public virtual Team GuestTeam { get; set; } } public