Translating SQL results to LINq with join of literal - sql

Question

All,
This is my first post to this forum and I have searched all throughout this site to find an answer to my question, but it looks like there is not an example of what I need to do.
Below is a SQL query I need to adapt to a LINQ statement:
select COUNT(pe2.*)
from SomeTable pe1
inner join SomeTable pe2 on (pe2.Id=pe1.Id and pe2.TypeCode='X')
where pe1.TypeCode='Y'
I have tried to join this as illustrated below, but it doesn't work:
var query = (from pe2 in SomeTable
join pe1 in SomeTable
on new { pe1.Id } equals new {pe2.Id }
where pe2.TypeCode == "X"
&& pe1.TypeCode == "Y"
select pe2).Count();

Answer 1

Since the TypeCode is HardCoded you can pass it to the where clause
select pe2.*
from SomeTable pe1
inner join SomeTable pe2 on pe2.Id=pe1.Id
where pe1.TypeCode='Y'
and pe2.TypeCode='X'
And here it's how I would do it in linq
var l1 = new List<dynamic> { new { Id = 1, Code = "X" }, new { Id = 2, Code = "Y" } };
var l2 = new List<dynamic> { new { Id = 1, Code = "Y" }, new { Id = 2, Code = "X" } };
//lambda expression
l1.Join(l2,
x => x.Id,
y => y.Id,
(x, y) => new { Pe1 = x, Pe2 = y })
.Where(x => x.Pe1.Code == "Y" && x.Pe2.Code == "X")
.Select(x => x.Pe2);
//query...
from x in l1
join y in l2 on x.Id equals y.Id
where x.Code == "Y"
&& y.Code == "X"
select y
from x in l1
from y in l2
where x.Id == y.Id
&& x.Code == "Y"
&& y.Code == "X"
select y