CODEWITHSUNDEEP
c#.netlinqforeachenumeration
smoothgrips
smoothgrips

Reputation: 417

Enumerating over Linq query results

I have some .NET 4.5 code:

var result = db.storedProcedure(param)
if (!result.Any()) { return; }
foreach (var entry in result)
{
    // Some code...
}

At the foreach, an exception is throw:

The query results cannot be enumerated more than once.

How can I check if result is empty? I've also tried if (result.Count() == 0) and that also throws the same exception at the foreach loop. I've also tried foreach (var entry in result.ToList()) and that also throws the same exception.

I have tried following the suggestions here and here, with no luck.

I've also tried:

var result = db.storedProcedure(param)
if (!result.Any()) { return; }
var resultList = result.ToList();
foreach (var entry in resultList) {}

And I still get the same exception at that foreach loop as well.

There must be some way to easily check if a Linq result set is empty. What am I doing wrong?

Upvotes: 2

Views: 916

Answers (2)

Corey Adler
Corey Adler

Reputation: 16137

Why do you even to make that check at all? Your loop won't even run at all if there's nothing in result. Just have this:

var result = db.storedProcedure(param)
foreach (var entry in result)
{
    // Some code...
}

return;

Upvotes: 2

Selman Genç
Selman Genç

Reputation: 101681

Just put the result into a List before iterating:

var result = db.storedProcedure(param).ToList();
if (result.Count == 0) { return; }

Upvotes: 7

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