CODEWITHSUNDEEP
linqentity-framework-core
huang
huang

Reputation: 1167

How to select 2 objects from 2 tables in one query?

I want to get the below result in one query by linq methods such as .Where, .Select etc., is it possible?

Inner join is the better.

new {
    Blog = MyDbContext.Blogs.SingleOrDefault(b => b.Url == "xxx.com"),
    Post = MyDbContext.Posts.SingleOrDefault(p => p.Blog.Url == "xxx.com" &&
                                                  p.Author == "Jack")
}

Models:

public class Blog 
{
    public int BlogId { get; set; }
    public string Url { get; set; }

    public List<Post> Posts { get; set; }
}

public class Post 
{
    public int PostId { get; set; }
    public string Author { get; set; }

    public Blog Blog { get; set; }
}

public class MyDbContext 
{
    public DbSet<Blog> Blogs { get; set; }
    public DbSet<Post> Posts { get; set; }
}

Upvotes: 0

Views: 76

Answers (1)

NetMage
NetMage

Reputation: 26926

var ans = MyDbContext.Blogs.Where(b => b.Url == "xxx.com")
                           .Select(b => new {
                                   Blog = b,
                                   Post = b.Posts.Where(p => p.Author == "Jack").FirstOrDefault()
                            })
                            .SingleOrDefault();

Upvotes: 1

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