Compare two IQueryable instances

Question

I have two IQueryable instances - objIQuerableA and objIQueryableB and I want to obtain only elements that are present in objIQuerableA and not in objIQuerableB .

One way is to use a foreach loop but I wonder if there is a better method.

Answer 1

简单直接。

var result = objIQuerableA.Except(objIQuerableB);

Answer 2

The title actually says compare two IQueryables. If you wanted to actually do a compare to determine if both IQueryable contain the same results in a single query....

var aExceptB = objIQuerableA.Except(objIQuerableB);
var bExceptA = objIQuerableB.Except(objIQuerableA);
var symmetricDiff = aExceptB.Union(bExceptA);
bool areDifferent = symmetricDiff.Any();