Session: Querying: How to Work with Suggestions

The Suggestion feature is available through query extension methods. It gives you the ability to find word similarities using string distance algorithms.

Syntax

ISuggestionQuery<T> SuggestUsing<T>(SuggestionBase suggestion);

ISuggestionQuery<T> SuggestUsing<T>(Action<ISuggestionBuilder<T>> builder);

Builder

ISuggestionOperations<T> ByField(string fieldName, string term);

ISuggestionOperations<T> ByField(string fieldName, string[] terms);

ISuggestionOperations<T> ByField(Expression<Func<T, object>> path, string term);

ISuggestionOperations<T> ByField(Expression<Func<T, object>> path, string[] terms);

ISuggestionOperations<T> WithOptions(SuggestionOptions options);

ISuggestionOperations<T> WithDisplayName(string displayName);

Options

public int PageSize { get; set; } = 15;

public StringDistanceTypes? Distance { get; set; } = StringDistanceTypes.Levenshtein;

public float? Accuracy { get; set; } = 0.5f;

public SuggestionSortMode SortMode { get; set; } = SuggestionSortMode.Popularity;

Multiple suggestions

You are able to ask for multiple suggestions using a single query.

ISuggestionQuery<T> AndSuggestUsing(SuggestionBase suggestion);

ISuggestionQuery<T> AndSuggestUsing(Action<ISuggestionBuilder<T>> builder);

Example I

Dictionary<string, SuggestionResult> suggestions = session
    .Query<Employee, Employees_ByFullName>()
    .SuggestUsing(builder => builder
        .ByField("FullName", "johne")
        .WithOptions(new SuggestionOptions
        {
            Accuracy = 0.4f,
            PageSize = 5,
            Distance = StringDistanceTypes.JaroWinkler,
            SortMode = SuggestionSortMode.Popularity
        }))
    .Execute();

Dictionary<string, SuggestionResult> suggestions = await asyncSession
    .Query<Employee, Employees_ByFullName>()
    .SuggestUsing(builder => builder
        .ByField("FullName", "johne")
        .WithOptions(new SuggestionOptions
        {
            Accuracy = 0.4f,
            PageSize = 5,
            Distance = StringDistanceTypes.JaroWinkler,
            SortMode = SuggestionSortMode.Popularity
        }))
    .ExecuteAsync();

from index 'Employees/ByFullName' 
select suggest('FullName', 'johne', '{ "Accuracy" : 0.4, "PageSize" : 5, "Distance" : "JaroWinkler", "SortMode" : "Popularity" }')

Example II

Dictionary<string, SuggestionResult> suggestions = session
    .Query<Employee, Employees_ByFullName>()
    .SuggestUsing(new SuggestionWithTerm("FullName") { Term = "johne" })
    .Execute();

Dictionary<string, SuggestionResult> suggestions = await asyncSession
    .Query<Employee, Employees_ByFullName>()
    .SuggestUsing(new SuggestionWithTerm("FullName") { Term = "johne" })
    .ExecuteAsync();

from index 'Employees/ByFullName' 
select suggest('FullName', 'johne')

Example III

Looking for suggestions with dynamic query usage for multiple fields:

Dictionary<string, SuggestionResult> suggestions = session.Query<Employee>()
    .SuggestUsing(x => x
        .ByField(y => y.FirstName, "johne")
        .WithDisplayName("CustomLastName"))
    .AndSuggestUsing(x => x
        .ByField(y => y.LastName, "owen"))
    .Execute();

Dictionary<string, SuggestionResult> suggestions = await asyncSession.Query<Employee>()
    .SuggestUsing(x => x
        .ByField(y => y.FirstName, "johne")
        .WithDisplayName("CustomFirstName"))
    .AndSuggestUsing(x => x
        .ByField(y => y.LastName, "owen"))
    .ExecuteAsync();

from Employees 
select suggest('FirstName', 'johne') as CustomFirstName, suggest('LastName', 'owen')