The query results cannot be enumerated more than once in LINQ

Question

this code:

using (DataClassesDataContext db = new DataClassesDataContext())
{
    IEnumerable<view_subject> results = db.ExecuteQuery<view_subject>(query);

    if (dataBind)
    {
        GridViewSearchResults.DataSource = results;
        GridViewSearchResults.DataBind();
    }

    return results.Count();
}

Throws me an exception: The query results cannot be enumerated more than once. And I dont understand why? Can somebody please help me?

Did you look for duplicate questions before asking? Look down the "related" questions at the side of this... — Jon Skeet, Jul 29 '14 at 18:05
there is similar question on SO http://stackoverflow.com/questions/5723555/the-result-of-a-query-cannot-be-enumerated-more-than-once — Vlad Bezden, Jul 29 '14 at 18:17

Vlad Bezden · Answer 1 · 2014-07-29T18:12:29.847

1

Using ToList() will retrieve all records from DB, and now it works on data instead of database query.

using (DataClassesDataContext db = new DataClassesDataContext())
{
    List<view_subject> results = db.ExecuteQuery<view_subject>(query).ToList();

    if (dataBind)
    {
        GridViewSearchResults.DataSource = results;
        GridViewSearchResults.DataBind();
    }

    return results.Count();
}

edited Jul 29 '14 at 18:12

answered Jul 29 '14 at 18:06

Vlad Bezden

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An explanation of what you did any why it solves the problem would be helpful here. – Andrew Barber Jul 29 '14 at 18:07
@AndrewBarber you beat me :) . I added explanation as well. – Vlad Bezden Jul 29 '14 at 18:15

The query results cannot be enumerated more than once in LINQ

1 Answers1