C# Linq group by multiple fields with ICollection

I’m trying to create a query between 2 tables that are defined as following

public class Article
{
    public long ID { get; set; }
    public int Language { get; set; }
    public string? Title { get; set; }
    public virtual ICollection<Tag>? Tags { get; set; }
}

public class Tag
{
    public long ID { get; set; }
    public string? Description { get; set; }
    public virtual int Language { get; set; }
    public string? Name { get; set; }
    public virtual ICollection<Article>? Articles { get; set; }
}

What I like to do is to have the list of tags for a Language with a count of the articles for each tag. For example, I create an article with this code

Article a1 = new Article()
{
    ID = 1,
    Language = 1,
    Body = "B1",
    Title = "Title1",
    Tags = new Tag[] {
        new Tag()
        {
            ID = 1,
            Language = 1,
            Name = "L1",
        },
        new Tag()
        {
            ID = 2,
            Language = 1,
            Name = "L2"
        }
    }
};

Then, I add another Article with the same tags. What I expect is to have a query that returns to me a list like this one:

The function I wrote is the following

Expression<Func<Tag, bool>> fnz = r => r.Language == lang;
List<LanguageTag> list = context.Tags.Where(fnz)
                        .GroupBy(t => new { t.Language, t.Name })
                        .Select(
                        r => new LanguageTag()
                        {
                            Language = r.Select(a => a.Language).FirstOrDefault(),
                            TagId = r.Select(a => a.ID).FirstOrDefault(),
                            TagName = r.Select(a => a.Name).FirstOrDefault(),
                            TagsCount = r.Select(a => a.Articles).Count()
                        }).ToList();

With this query, the result is that each Tag has a count equal to 1. How can I count the articles from each tag?

>Solution :

It seems to me you don’t need a ‘group by’ at all. Since you have the required relationships and also you don’t require anything from the Articles table the below query should work for you.

const reuult = context.Tags.Where(fnz)
            .Select(r=> new LanguageTag {
    Language = r.Language),
    TagId = r.ID,
    TagName = r.Name,
    TagsCount = r.Articles.Count()
}).ToList();