Help writing a linq query in subsonic
I'm busy writing some extension methods and so far have been going fine. I have a method getCities that takes in an IQueryable qry and is supposed to return all of the regions in qry that have a region type of city.
I tried using linq to do it, but gave up and am currently using a for loop. It works, but its bugging me. I have commented out at the bottom the linq statement i have come up with, that doesn't work.
The for loop returns records correctly, the linq query i commented out never returns anything.
A region can only h开发者_运维知识库ave 1 Region_Type, but subsonic makes it a collection, which is why i'm using item.Region_Types.First() to get the regions Region_Type.
public static IQueryable<Region> getCities(this IQueryable<Region> qry)
{
List<Region> returnCol = new List<Region>();
foreach (var item in qry)
{
if (item.Region_Types.First().Name.ToLower().Trim().Equals("city"))
{
returnCol.Add(item);
}
}
return returnCol.AsQueryable();
//return qry.Where(t => t.Region_Types.First().Name.ToLower().Trim().Equals("city"));
}
Where() returns an IEnumerable, not an IQueryable, you should use .AsQueryable() at the end of the statement:
return qry.Where(t => t.Region_Types.First().Name.ToLower().Trim().Equals("city")).AsQueryable();
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