Why is the query operator 'ElementAt' is not supported in LINQ to SQL?

Question

In LINQ to SQL, I get the exception \"The query operator \'ElementAt\' is not supported.\" When trying to use the ElementAt extension method on an IQueryable return

Answer 1

It is odd, in particular because Skip() is supported. Could you, for example, do:

var obj = source.Skip(index).First();

?

Answer 2

From MSDN, Standard Query Operator Translation (LINQ to SQL) - this article contains the full list of operators that haven't been translated:

• TakeWhile , SkipWhile
• Reverse
• Last , LastOrDefault
• ElementAt , ElementAtOrDefault
• DefaultIfEmpty

Operators with No Translation

The following methods are not translated by LINQ to SQL. The most common reason is the difference between unordered multisets and sequences.

Operators

Rationale

...

ElementAt , ElementAtOrDefault

SQL queries operate on multisets, not on indexable sequences.