Multiple left join using lambda syntax in Entity Framework - entity-framework

Question

I have the following 3 tables
Courses
Id, SortOrder, CourseName, CourseArea, CourseFor
Students
Id, FullName
CourseStudents
CourseId, StudentId, CollegeId
Requirement:
Get all course students from the 'Medical' area for 'foreign' students available in College '125'. Include courses even if there are no students enrolled in it.
Working SQL query:
SELECT cr.Id, cr.CourseName, st.FullName
FROM dbo.Courses cr
LEFT JOIN dbo.CourseStudents cst ON cr.Id = cst.CourseId
AND cst.CollegeId = 125
LEFT JOIN dbo.Students st ON cst.StudentId = st.Id
WHERE
cr.CourseArea = 'Medical'
AND cr.CourseFor = 'Foreigner'
ORDER BY
cr.SortOrder, st.FullName
Can anyone help me with the lambda syntax (I tried GroupJoin)? While what I am looking for is the lambda syntax, the query syntax is also good to know.
UPDATE: I am very close, but still not complete
context.Courses
.GroupJoin(context.CourseStudents,
x => new { x.Id, CollegeId NOT IN COURSES TABLE :( },
y => new { Id = y.CourseId, y.CollegeId=125 },
(x, y) => new { Courses = x, CourseStudents = y })
.SelectMany(x => x.CourseStudents.DefaultIfEmpty(),
(x, y) => new { x.Courses, CourseStudents = y })
.GroupJoin(context.Students,
x => x.CourseStudents.StudentId,
y => y.Id,
(x, y) => new { CoursesCourseStudents = x, Students = y }
)
.SelectMany(x => x.Students.DefaultIfEmpty(),
(x, y) => new { x = x.CoursesCourseStudents, Students = y })
.Select(x => new
{
x.x.Courses.Id,
x.x.Courses.CourseName,
x.Students.FullName,
x.x.CourseStudents.CollegeId,
x.x.Courses.CourseFor,
x.x.Courses.CourseArea,
x.x.Courses.SortOrder
})
.Where(x => x.CourseFor == "Foreigner" && x.CourseArea == "Medical")
.OrderBy(x => x.SortOrder)
.ToList();

Answer 1

SOLUTION: I got it working by doing the following. See line 3 and 4.
context.Courses
.GroupJoin(context.CourseStudents,
x => new { x.Id, CollegeId=125 },
y => new { Id = y.CourseId, y.CollegeId },
(x, y) => new { Courses = x, CourseStudents = y })
.SelectMany(x => x.CourseStudents.DefaultIfEmpty(),
(x, y) => new { x.Courses, CourseStudents = y })
.GroupJoin(context.Students,
x => x.CourseStudents.StudentId,
y => y.Id,
(x, y) => new { CoursesCourseStudents = x, Students = y }
)
.SelectMany(x => x.Students.DefaultIfEmpty(),
(x, y) => new { x = x.CoursesCourseStudents, Students = y })
.Select(x => new
{
x.x.Courses.Id,
x.x.Courses.CourseName,
x.Students.FullName,
x.x.CourseStudents.CollegeId,
x.x.Courses.CourseFor,
x.x.Courses.CourseArea,
x.x.Courses.SortOrder
})
.Where(x => x.CourseFor == "Foreigner" && x.CourseArea == "Medical")
.OrderBy(x => x.SortOrder)
.ToList();