Use this tag for version specific questions about the 3.1 version of Entity Framework for .NET Core. When using this tag also include the more generic [entity-framework-core] tag where possible.
Questions tagged [ef-core-3.1]
698 questions
-1
votes
0 answers
How to use EF Core and LINQ query syntax to get entities and counts of their children
How would I use EF Core and LINQ query syntax to select entities and counts of their children. For example, select all Teams and a count of each team's Players. Note: the Team entity does not have a Players navigation property collection on it.
The…
NSouth
- 4,477
- 7
- 38
- 71
-1
votes
1 answer
updating child entity in parent entity gives duplicate violation key error
I have below classes spacetype and mastersection which is having below structure
public class SpaceType
{
public Guid Id { get; set; }
[ForeignKey("MasterSection")]
public string MasterSectionName { get; set; }
public virtual…
Enigma State
- 16,494
- 25
- 86
- 179
-1
votes
1 answer
How do I save data from xml file in related tables using ef core?
I am creating the associated table like in the photos below. How do I save data in my related tables via XML?
Sedat Sayer
- 13
- 4
-1
votes
1 answer
Unable to check if a list of int is completely contained in another int list
I have a list of int that represents service ids. and I want to make sure that all of those ids exist in the database.
In other words , I want to scan the list of ids and the table of services to make sure that all of these ids exist in the…
Ataa Aub
- 55
- 8
-1
votes
1 answer
Automapper.ProjectTo() is throwing null reference exception
I Have the following mapping :
CreateMap()
.ForMember(des => des.Code, src => src.MapFrom(s => s.Code))
.ForMember(des => des.Notes, src => src.MapFrom(s => s.FormNotes))
//other…
Mahamad Husen
- 69
- 9
-1
votes
1 answer
TypeLoadException when injecting Context in Worker
I currently have a Razor page application (Core 3.1) connected to a SQL Database with a Context using IdentityDbContext. When trying to use this same context in my Worker Service, I continue to get this error:
System.TypeLoadException: 'Method…
Andy Xufuris
- 658
- 2
- 9
- 30
-1
votes
1 answer
Order results by the length of varchar/nvarchar column value in EF Core
How can I order the results set by the length of column value in EF Core?
One of the entity properties is barcode, which I need to bring entities with shorter barcodes on top of the list while searching the value likeliness not exact match.
In SQL…
Mkhairy
- 137
- 2
- 9
-1
votes
2 answers
How to add translations to database after API response with EF Core?
I have a requirement to add a project and translate its description with an external API translation service into several languages (so they exist in the database and it's possible to fetch a project in different languages later). Since translation…
Vitalii Isaenko
- 741
- 1
- 10
- 30
-1
votes
1 answer
How to sort on DB side, if entities are not connected via Navigation (since it's not possible)
I want to have my EfCore query translated into the following SQL query:
select
c.blablabla
from
codes c
left join lookups l on c.codeId = l.entityid and l.languageCode = and l.lookuptype =…
Alexander
- 739
- 11
- 15
-1
votes
1 answer
How to efficiently filter children based on parent's attribute
I am looking for help with building a search bar. I have 3 database tables here: Case -> Exhibit -> Tasking. Case is Exhibit's parent and Exhibit is Tasking's parent. I have a table displaying info on a list of Taskings as well as their parent Id…
He Chuan
- 21
- 6
-1
votes
1 answer
Entity Framework "Include" does not load entity related tables
I have a project with ASP.NET Core 3.1 using Visual Studio 2019 (64 bit) and SQL Server 2019. When I run the backend it generates an error when I use Entity Framework's .Include to load data from a related table. It's strange that the same code…
DigitalDevGuy
- 43
- 1
- 10
-1
votes
2 answers
Setting properties using asp-for in MVC Core App with EF Core?
As I understand it from these docs: https://docs.microsoft.com/en-us/aspnet/core/mvc/views/tag-helpers/intro?view=aspnetcore-3.1 , asp-for is used to transfer values from input elements to backend C# class properties, for example:
Solacefire
- 7
- 2
-1
votes
1 answer
How to Convert XML output from Stored Procedure to C# object in Asp Net Core
SET ANSI_NULLS ON; GO SET QUOTED_IDENTIFIER ON; GO ALTER PROC
[dbo].[getStateWiseCompanyDetails] AS
BEGIN
With Data
AS (SELECT Companies.RegionId,
Companies.Code,
Companies.CompanyName,
…
Kadam Prajapati
- 13
- 4
-1
votes
1 answer
How many times to call .SaveChangesAsync() in .BeginTransaction() EF Core 3.1
Call SaveChangesAsync every changes like .Remove, .Update or .Add
using (var transaction = _unitOfWork.BeginTransaction())
{
try
{
var structureProfile = await…
Marco Torrecampo
- 143
- 1
- 10
-1
votes
1 answer
Expression of type 'System.Linq.IOrderedQueryable`1[Models.Option]' cannot be used for return type 'System.Linq.IOrderedEnumerable`1[Models.Option]
In the following Query, I want to Sort the Children List of a Parent based on Index Property, which I encounter with the following error ...
How to Fix it ?
Expression of type 'System.Linq.IOrderedQueryable`1[Models.Option]' cannot be used for…
Alireza Askari
- 25
- 1
- 2