Using Cross join in Asp .net Web API getting error - mysql

Question

Hi i am Using Cross join through in Asp .net Web API with a mysql database and getting the following error :
Error 1 Cannot implicitly convert type 'System.Linq.IQueryable' to 'System.Linq.IQueryable'. An explicit conversion exists (are you missing a cast?)
This is my controller code
private myappEntities db = new myappEntities();
public IQueryable<comment>GetPicturesandtheirCommnets()
{
var combo=from p in db.picturedetails
from c in db.comments
select new
{
p.iduser,p.idpictures,p.likes,p.nuditylevel,p.picTitle,p.pictime,p.fakeslevel,
c.comment1,c.ctime,c.idcomments,c.spamlevel,c.targetpictureid
};
return combo;
}
Why am i getting this error?? Any help?

Answer 1

Your query (combo) returns an anonymous type, and your method signature says you are returning an IQueryable<comment>. You can't return anonymous types from methods, so you have two options:
Option 1: Select just fields from the Comment table to return.
Option 2: Create a new class that includes details from Comments and PictureDetails, and modify your query to select new CommentAndPictureDetails (or whatever you name your class).
The modified query would look like this:
var combo=from p in db.picturedetails
from c in db.comments
select new CommentAndPictureDetails
{
IdUser = p.iduser,
IdPictures = p.idpictures,
Likes = p.likes,
NudityLevel = p.nuditylevel,
PicTitle = p.picTitle,
PicTime = p.pictime,
FakesLevel = p.fakeslevel,
Comment1 c.comment1,
CTime = c.ctime,
IdComments = c.idcomments,
SpamLevel = c.spamlevel,
TargetPictureId = c.targetpictureid
};
Your class declaration for CommentAndPictureDetails would be like so:
public class CommentAndPictureDetails
{
public string IdUser {get; set;}
// I don't know the data types, so you'll have to make sure
// the .NET type matches the DB type.
}