notrack | wide DNS server which blocks Tracking sites | DNS library

I discovered one problem while creating my project. If someone refer to the issue I will be grateful. In my project I use a layered model. The repository layer (data access layer) that communicates with the database (DB) and the service layer (business logic layer) in which services and objects are implemented (data transfer object).

As a result, there is a problem with the dbSet.Update method. When object (obj) comes into Update method as parameter, during the method call of the _db.Entry(dbSet.Local.FirstOrDefault(i => i.Id == obj.Id) ?? obj).State = EntityState.Modified or _db.Update(dbSet.Local.FirstOrDefault(i => i.Id == obj.Id) ?? obj) in the case of the first user's update (like from "view.xaml") obj is update and changes saving in the database (because dbSet.Local.FirstOrDefault(i => i.Id == obj.Id) returns null and obviously my obj gets into the _db.Update method). In case of a repeated user's update (in the "view.xaml" view) object obj -- when it gets into the _db.Update(dbSet.Local.FirstOrDefault(i => i.Id == obj.Id) ?? obj) method, it isn't take account, as the data context already tracks it and in the _db.Update method gets an object from dbSet.Local.FirstOrDefault(i => i.Id == obj.Id). Everything would be fine if this object in dbSet.Local was updated according to the type that comes from the user. However, this is not the case, it is tracked but not changed when the user edits its properties. It is not tracked properly rather due to the fact that I use services and, accordingly, data transfer object entities.

In view of the foregoing, I have a question. How to make to update entity (by a new modified object) that are tracked, or how to manually assign the necessary object in dbSet.Local to replace the one stored there? or how to make Microsoft.EntityFrameworkCore.ChangeTracking not track changes to my objects in any way?

In order to make changes not tracked I used the QueryTrackingBehavior.NoTracking parameter for the DbContextOptionsBuilder entity, but this only helps on the first load, and tracking is still used when the data is updated further. I also used the dbSet.Local.Clear() methods, but this is a bad idea, as data updating due to the deletion of the previous data from the database (like delete 20 rows from table and add one updated).

I have this model

In my database when I filter Ofertas by Organismo I get these results

Where I see that organismo with id=6 has 2 different Ofertas

When I translate this query to EF in my Web API

I have a database table with 7 columns for my blog using EF Core, and I am trying to create a multidimensional array in my c# code so that on page load I can retrieve the values from the DB and then assign the values in my controller to text fields in bootstrap cards. So card.1 will have details from Row.1 in the DB, card .2 will have details from Row.2 in the DB etc.

This is my database model:

I have an EFCore query that, for the same parameter values and same database state, sometimes throws a NullReferenceException. Any ideas how I can identify where the problem lies?

The query looks like this (yes it's a somewhat complicated db structure):

The dbcontext tracking behaviour is set to NoTracking, but I still get a fail in the test.

BaseDbContext in this context does not have any relevant code compared to IdentityDbContext provided by EF. Also is the same with BaseUser, where it is basically only IdentityUser.

Method for creating DbContext:

.net 5.0 c# Razor

I have been trying for a few days to dynamically populate a list with 164 country names that sit in a DB column. I have worked through various sources online and 'nearly' have it working, but I'm stuck at the final hurdle. The list populates one name at a time, overwriting the previous one each time. Only the final value from the DB column displays in the view. HTML @_loc[Model.CountryHeading] Country


Controller

I'm trying to use Microsoft.AspNetCore.Mvc.ActionContext in my controller but I get this error even thought I did the DI inside MyController .. I don't know how to fix it, please help

I am developing a CRM by .net core mvc and EF which needs a lot of DB connection to retrieve and update information. From time to time I face this error during debugging, this is a big project with a lot of users I don't know how it will work in real usage!

Cannot access a disposed context instance. A common cause of this error is disposing a context instance that was resolved from dependency injection and then later trying to use the same context instance elsewhere in your application. This may occur if you are calling 'Dispose' on the context instance, or wrapping it in a using statement. If you are using dependency injection, you should let the dependency injection container take care of disposing context instances.\r\nObject name: 'XXX'.

before I used this setting in startup.cs:

I am implementing an api using .net 5. I have a student class which have a property with address type(value object according to ddd).