Working with SQL views in Entity Framework Core

In Entity Framework Core 2.1 we can use Query Types as Yuriy N suggested.

A more detailed article on how to use them can be found here

The most straight forward approach according to the article’s examples would be:

1.We have for example the following entity Models to manage publications

public class Magazine
{
  public int MagazineId { get; set; }
  public string Name { get; set; }
  public string Publisher { get; set; }
  public List<Article> Articles { get; set; }
}

public class Article
{
  public int ArticleId { get; set; }
  public string Title { get; set; }
  public int MagazineId { get; set; }
  public DateTime PublishDate { get;  set; }
  public Author Author { get; set; }
  public int AuthorId { get; set; }
}
public class Author
{
  public int AuthorId { get; set; }
  public string Name { get; set; }
  public List<Article> Articles { get; set; }
}

2.We have a view called AuthorArticleCounts, defined to return the name and number of articles an author has written

SELECT
  a.AuthorName,
  Count(r.ArticleId) as ArticleCount
from Authors a
  JOIN Articles r on r.AuthorId = a.AuthorId
GROUP BY a.AuthorName

3.We go and create a model to be used for the View

public class AuthorArticleCount
{
  public string AuthorName { get; private set; }
  public int ArticleCount { get; private set; }
}

4.We create after that a DbQuery property in my DbContext to consume the view results inside the Model

public DbQuery<AuthorArticleCount> AuthorArticleCounts{get;set;}

4.1. You might need to override OnModelCreating() and set up the View especially if you have different view name than your Class.

protected override void OnModelCreating(ModelBuilder modelBuilder)
{
    modelBuilder.Query<AuthorArticleCount>().ToView("AuthorArticleCount");
}

5.Finally we can easily get the results of the View like this.

var results=_context.AuthorArticleCounts.ToList();

UPDATE
According to ssougnez’s comment

It’s worth noting that DbQuery won’t be/is not supported anymore in EF
Core 3.0. See here

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