How does LINQ's “Where” method works?

Question

Exactly how LINQ\'s \"where\" method is defined? I\'m guessing implementation is something like this:

public static IEnumerable Where ( this partialPare         


        

Answer 1

The following "pseudo"-code blocks give the same code:

// first
from item in sequence
where expression
select item;

// second
sequence.Where(item => expression);

It does not matter how many comparisons that are made in expression as long as it yields a boolean result. It's still one expression.

This means that the following two are also identical:

// first
from c in context.Con
where ( c.Col1 == c.Col2 || c.Col3 == c.Col4 )
select c;

// second
context.Con.Where(c => c.Col1 == c.Col2 || c.Col3 == c.Col4);