ElasticSearch with NEST query issue

Question

Forgive my newbish-ness as I am new to both ElasticSearch and NEST. I am working on a prototype to evaluate ElasticSearch in a .NET solution being implemented. The prototype compiles and does seem to search, but isn't properly returning results. It only returns results on a few keywords, lowercase only, while ignoring others and returning nothing. I am thinking there's something wrong in my query. Here's the query part (assume connection info and default index specified and built).

// string searchString to be searched against ProductName and Description fields.            
var searchResults = client.Search<Product>(s=>s
            .From(0)
            .Size(100)
            .Query(q=>q.Term(p=>p.ProductName, searchString) || 
                q.Term(p=>p.Description, searchString)
            ));

Here's the model if needed:

[ElasticType(IdProperty = "ProductID")]
public class Product
{
    [ScaffoldColumn(false)]
    [JsonIgnore]
    public int ProductID { get; set; }

    [Required, StringLength(100), Display(Name = "Name")]
    public string ProductName { get; set; }

    [Required, StringLength(10000), Display(Name = "Product Description"), DataType(DataType.MultilineText)]
    public string Description { get; set; }

    public string ImagePath { get; set; }

    [Display(Name = "Price")]
    public double? UnitPrice { get; set; }

    public int? CategoryID { get; set; }
    [JsonIgnore]
    public virtual Category Category { get; set; }
}

Appreciate the help!

Do you really intend for productname and description to match your search string? — Josh C.
I want it to match either, and yes I did use the OR operator as well with little change. — Michael
UPDATE: Okay, apparently I did goof up the OR operator before. Now the searching is working better, except it seems to be messing up the case of letters.... e.g. "Custom" returns nothing, but "custom" returns "Kat Custom Car"... — Michael

Greg Marzouka Greg Marzouka · Accepted Answer · 2014-08-28T03:43:16

Your issue here is that you're using term queries, which are not analyzed and thus are case-sensitive.

Try using a match query (which is analyzed) instead:

var searchResults = client.Search<Product>(s => s
    .From(0)
    .Size(100)
    .Query(q => 
        q.Match(m => m.OnField(p => p.ProductName).Query(searchString)) || 
        q.Match(m => m.OnField(p => p.Description).Query(searchString))
     )
);

Taking it one step further- since you are querying the same text on two different fields, you can use a multi match query instead of combining the two term queries:

var searchResults = client.Search<Product>(s => s
    .From(0)
    .Size(100)
    .Query(q => q
        .MultiMatch(m => m
            .OnFields(p => p.Product, p => p.Description)
            .Query(searchText)
        )
     )
);

For a better understanding of analysis, the mapping and analysis section from The Definitive Guide is a great read.

ElasticSearch with NEST query issue

1 Answers