How to achieve Left Excluding JOIN using LINQ?

Question

How to achieve Left Excluding JOIN using LINQ?

In SQL:

SELECT  
FROM Table_A A
LEFT JOIN Table_B B
ON A.Key = B.Key
WHERE B.Key I         


        

Answer 1

An even faster way

var result = from a in Table_A
    where !Table_B.Select(b => b.Key).Contains(a.Key)
    select new { ... };