Wildcard

[markwriter]

I was hoping to use the wildcard to find "stationary" and "stationery" using %. Searching for "station%ry" did not return any results - "stationary stationery" works as expected.

Enclosed is Json.
umClasses.zip

var jsonFile = File.ReadAllText("C:\Users\manderson\Documents\umClasses.json");
var searchModels =
JsonConvert.DeserializeObject<System.Collections.Generic.List>(jsonFile);
var index = new FullTextIndexBuilder()
.WithDefaultTokenization(o => o.WithStemming())
.WithQueryParser(o => o.WithDefaultJoiningOperator(QueryTermJoinOperatorKind.Or))
.WithTextExtractor()
.WithObjectTokenization(
itemOptions => itemOptions
.WithKey(c => c.ClassDescriptionId)
.WithField("GLGuidelines", f => f.GLGuidelines)
).Build();
index.AddRangeAsync(searchModels);

        //Was hoping these two counts would be the same
        var searchResults = index?.Search("stationary stationery").Count();
        var searchResults2 = index?.Search("station%ry").Count();

[mikegoatly]

The wierdness you're seeing is an unfortunate side-effect of using stemming in the index. The words "stationary" and "stationery" get stemmed to different forms:

Console.WriteLine(index.DefaultTokenizer.Process("stationary")[0].Value);
Console.WriteLine(index.DefaultTokenizer.Process("stationery")[0].Value);

// Output:
// STATIONARI
// STATIONERI

This makes wildcard matching behave unexpectedly - there's not really an effective way for LIFTI to stem a wildcard search like this to its index counterpart.

Your options in this case are:

• use an ends with wildcard to perform the search, e.g. station* - you could make it even more selective by requiring that at least one character appears after "station": station%*
• Armed with the knowledge of how the words are stemmed, search with station%ri

[markwriter]

Got it - I appreciate the answer & suggestions.