I've got some data that I need to return some of its related data and put it all in a model. I have all the appropriate fields setup in my model, and looks like this:
public class ComputerModel
{
public int MachineId { get; set; }
public int GroupId { get; set; }
public int SoftwareVersionId { get; set; }
public string GroupName { get; set; }
public string SoftwareVersion { get; set; }
public string IPAddress { get; set; }
public string HostName { get; set; }
public string MACAddress { get; set; }
public string Title { get; set; }
public bool IsIGMonitor { get; set; }
public string UpTime { get; set; }
public DateTime DateEntered { get; set; }
public string EnteredBy { get; set; }
public Nullable<DateTime> DateUpdated { get; set; }
public string UpdatedBy { get; set; }
public ICollection<MachineRole> MachineRoles { get; set; }
public ICollection<Role> Roles { get; set; }
}
Here's the linq statement I'm trying to use:
var query = (from m in unitOfWork.Context.Machines
join u in unitOfWork.Context.Users
on m.EnteredBy equals u.UserId into EntByUser
from EnteredByUser in EntByUser.DefaultIfEmpty()
join u2 in unitOfWork.Context.Users
on m.UpdatedBy equals u2.UserId into UpdByUser
from UpdatedByUser in UpdByUser.DefaultIfEmpty()
join g in unitOfWork.Context.Groups
on m.GroupId equals g.GroupId into Grp
from Groups in Grp.DefaultIfEmpty()
join s in unitOfWork.Context.SoftwareVersions
on m.SoftwareVersionId equals s.SoftwareVersionId into SW
from SoftwareVersions in SW.DefaultIfEmpty()
join mr in unitOfWork.Context.MachineRoles
on m.MachineId equals mr.MachineId into MachRoles
from MachineRoles in MachRoles.DefaultIfEmpty()
join r in unitOfWork.Context.Roles
on MachineRoles.RoleId equals r.RoleId into Rolz
from Rolz2 in Rolz.DefaultIfEmpty()
select new ComputerModel()
{
MachineId = m.MachineId,
GroupId = m.GroupId,
SoftwareVersionId = m.SoftwareVersionId,
GroupName = Groups.GroupName,
SoftwareVersion = SoftwareVersions.Version,
IPAddress = m.IPAddress,
HostName = m.HostName,
MACAddress = m.MACAddress,
Title = m.Title,
IsIGMonitor = m.IsIGMonitor,
UpTime = m.UpTime,
DateEntered = m.DateEntered,
DateUpdated = m.DateUpdated,
EnteredBy = EnteredByUser.FirstName + " " + EnteredByUser.LastName,
UpdatedBy = UpdatedByUser.FirstName + " " + UpdatedByUser.LastName,
MachineRoles = m.MachineRoles,
Roles = ?????
}).ToList();
I can get MachineRoles to populate but I cannot get Roles to populate. I've tried Roles = Rolz2
but Rolz returns a single instance of Role, not a collection.
How can I get this query to return Machines and the related data for both MachineRoles and Roles?
I've looked at the following articles but haven't had much luck:
This SO Article
Loading Related Data - MSDN
Using Include with Entity Framework
UPDATE
I notice if I remove my model and use an anonymous type, then I don't get any errors:
select new ()
{
GroupName = Groups.GroupName,
......
}).ToList();
But this doesn't help me in my project because I need to use a Model for the data.
If all the above tables are related via PK-FK relationship you can use linq lambda functions .Include() to include related tables and then use Navigation properties to access data.
If the tables are not related you can use LINQ left joins as shown in http://www.devcurry.com/2011/01/linq-left-join-example-in-c.html.
It looks like you need a mix of inner and left joins. The above example and only achieve inner joins.