Question

I am using linq to sql. I am running a query which uses a function to return the right record. I am using a function so I can use if statement which I dont know how to do it within the linq clause. The code is copied below. It returns an error: “GetPageOwner(int 32) has no supported translation to sql” what am i doing wrong? How to fix it to get the same results?

   return (from page select new Result
        {

            pageOwner = GetPageOwner(page.page_id)
        });


    public Post GetPageOwner(int pageid)
    {

        var posts = (from dp in db.Posts where dp.pageid == pageid select dp);
        var returned = posts;

        if (posts.Count() > 0)
        {
            var latest = posts.OrderByDescending(o => o.Date).FirstOrDefault();
            var sharedsamedayaslatest = (from p in posts where p.Date.AddDays(1) >= latest.Date select p);
            if (sharedsamedayaslatest.Count() > 1)
            {
                var followedpost = (from p in posts from s in db.Subscriptions where s.Subscriber == UID && s.Subscribedto == p.UserId select p);
                var count = followedpost.Count();
                if (count == 1)
                {
                    returned = followedpost;
                }
                else if (count > 1)
                {
                    returned = (from s in followedpost let reposts = GetPostReposts(s.id) let rating = GetPostRating(s.id) let score = reposts + rating orderby score descending select s);
                }
                else
                { 
                    //no follower shared this post so return the most liked
                    returned = (from s in sharedsamedayaslatest let reposts = GetPostReposts(s.id) let rating = GetPostRating(s.id) let score = reposts + rating orderby score descending select s);
                }
            }
            else
            {
                //no shares on the day the latest share
                returned = sharedsamedayaslatest;
            }
        }
        else
        {
            //only one post
            returned = posts;
        }


        return returned.FirstOrDefault(); //order by userid gets a random one



    }

Answer 1

Linq to sql has to translate functions from .net into sql. Not all .net functions have an equivalent in sql, and ones written by you definitely don’t have one.

That being said you can implement your function as a stored procedure and use it in your linq query.