dal | Ctrip Database Access Layer | Database library

I have a project it's about real estate so I created tables user and linked it with estates, and I learnt about identity.

When I migrate it hides the user table because the ASP.NET Core identity already has a users table, so how can I link asp.net user to users or how to link asp.net user to identity user

I am trying to call Firebase functions inside a "DAL" class as I want to create some abstraction. I cannot figure out how to return a variable from inside the callback, or how to pass in a callback to execute from the controller class I created. How would I make UserExistsInFirebase async and call that from a controller class like

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 am scraping the stock prices, and names from Yahoo's finance website. After making a dataframe with three columns "Name", "Code", and "Price" and representing the passed index variable. I want to go to another loop and add a column to the original dataframe with updated prices. But when I add the column it creates NaN values for my original data. What do I need to do to correctly place the indexes and not disturb the original dataframe data?

Given the following example for an Entity-Definition, there is a foreign key defined. As a developer and database engineer i would expect that the command dal:create:schema would also create the expected foreign keys. But this is not the case.

I'm working on xamarin project and using Entity Framework Core to access database. I know it's not a good solution but i decided to do it without application server.

The DAL layer is using repository pattern and BL layer is using facade pattern with mappers. On the DAL layer i want to create IAsyncEnumerable of entities and on BL i want to make IAsyncEnumerable of models.

The first and the second example does not work, It ends on System.ObjectDisposedException "Cannot access a disposed context instance..." Why? ToList() works good, ToListAsync() works good.

Ends on System.ObjectDisposedException

There are lots of EF master-detail questions, I've looked through most of them. I can't find any that address the syntax approach I'm using which include transformation of the EF query results into a new business model, but I'm sure there is a way.

Here is the business model to emit from the DAL (header properties not shown)

I'm writing an Application that contains a nested structure like this one:

Here is my input DataFrame