Convert multi table sql join with derived table to Linq - sql

Question

I have a working SQL query as shown below. I want to create an equivalent Linq query. Not have much success.
select u.Id as userId, u.CustomerId, a.Id as appId, a.Created as appCreated
from EO_AppUsers u
left join EO_Policies p on (u.Id = p.AppUser_Id)
CROSS APPLY (
select TOP 1 id, created, AppUser_Id
from EO_Applications d
WHERE d.AppUser_id = u.id
order by Created desc ) a
CREATE TABLE [dbo].[EO_AppUsers] (
[Id] NVARCHAR (128) NOT NULL
CREATE TABLE [dbo].[EO_Policies] (
[Id] NVARCHAR (128) NOT NULL,
[AppUser_Id] NVARCHAR (128) NULL,
CREATE TABLE [dbo].[EO_Applications] (
[Id] NVARCHAR (128) NOT NULL,
[Created] DATETIME2 (7) NOT NULL,
[AppUser_Id] NVARCHAR (128) NULL,
EO_AppUsers has a EO_Policies and zero or more EO_Applications.
The SQL creates a report of all EO_AppUsers and associated EO_Policies and the latest/newest EO_Applications
The following handles returning EO_AppUsers and EO_Policies but is missing the EO_Applications. It needs the CROSS APPLY from the SQL query above.
var q = (from u in dbContext.EO_AppUsers
join p in dbContext.EO_Policies on u.Id equals p.AppUser.Id
//join a in dbContext.EO_Applications on u.Id equals a.AppUser.Id
select new
{
/// return fields from EO_AppUsers, EO_Policies and EO_Applications
});

Answer 1

You can try this linq query.
from u in EO_AppUsers
join p in EO_Policies on u.Id equals p.AppUser_Id into pl
from lp in pl.DefaultIfEmpty()
from a in EO_Applications.Where(d => d.AppUser_Id == u.Id)
.OrderByDescending(d => d.Created)
.Take(1)
.DefaultIfEmpty()
select new { userId = u.Id,
u.CustomerId,
appId = a.Id,
appCreated = a.Created,
polId = lp.Id
}