ElasticSearch-Net NEST search

Question

I'm using NEST lib, and very basic setup according to the document. I've added index, mapping, etc.

But when I try to do search it always gives me, "An item with the same key has already been added". It confused me alot on what the error means.

        var result = client.Search<Contact>(s => s
            .AllIndices()
            .From(0)
            .Size(10)
            .Query(q => q
                .MatchAll())
        );

Here is the Contact:

public class Contact
{
    public Guid Id { get; set; }
    public Guid TenantId { get; set; }
    public string Title { get; set; }
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public DateTime ModifiedDate { get; set; }
    public IList<string> Emails { get; set; }
}

Are you sure this peace of code is causing error? Which version of ES, NEST do you sue? — Rob
Your example is working like a charm with NEST 1.5.0. May you share more details? — Rob
Rob, interesting that if I don't use any mapping it works fine, but after I put my custom mappings in it gives me that mysterious error, "An item with the same key has already been added". — Fei

samjudson samjudson · Accepted Answer · 2015-05-13T19:53:26

You likely have a contact in elastic with the same email address twice. You could change the Email property to a string array perhaps?

ElasticSearch-Net NEST search

1 Answers