Sitecore search: Get results term by term - linq

Question

Here, I am trying to get search results for multiple terms. Say fulltext="Lee jeans", then regexresult={"lee","jeans"}.
Code :
IProviderSearchContext searchContext = index.CreateSearchContext();
IQueryable<SearchItem> scQuery = searchContext.GetQueryable<SearchItem>();
var predicate = PredicateBuilder.True<SearchItem>();
//checking if the fulltext includes terms within " "
var regexResult = SearchRegexHelper.getSearchRegexResult(fulltext);
regexResult.Remove(" ");
foreach (string term in regexResult)
{
predicate = predicate.Or(p => p.TextContent.Contains(term));
}
scQuery = scQuery.Where(predicate);
IEnumerable<SearchHit<SearchItem>> results = scQuery.GetResults().Hits;
results=sortResult(results);
Sorting is based on sitecore fields:
switch (query.Sort)
{
case SearchQuerySort.Date:
results = results.OrderBy(x => GetValue(x.Document, FieldNames.StartDate));
break;
case SearchQuerySort.Alphabetically:
results = results.OrderBy(x => GetValue(x.Document, FieldNames.Profile));
break;
case SearchQuerySort.Default:
default:
results = results.OrderByDescending(x => GetValue(x.Document, FieldNames.Updated));
break;
}
Now, what i need is to have results for "lee" first and sort them and then find results for "jeans" and sort them. The final search result will have the concatenated sets of sorted items for "lee" first and then for "jeans".
Thus we would have to get results for "lee" first and then results for "jeans"
Is there a way to get results term by term ?

Answer 1

You can use Query-Time Boosting to give the terms more relevance and therefore affect the ranking:
Sitecore 7: Six Types of Search Boosting
Lucene Boost With LINQ in Sitecore 7 ContentSearch
You want to give the first term the highest boost, and then gradually reduce for each additional term:
var regexResult = SearchRegexHelper.getSearchRegexResult(fulltext);
regexResult.Remove(" ");
float boost = regexResult.Count();
foreach (string term in regexResult)
{
predicate = predicate.Or(p => p.TextContent.Contains(term)).Boost(boost--);
}
EDIT:
Boosting and sorting in the same query is not possible, at least, the sorting will undo the "relevance" based sorting that was returned due to boosting.
Alternative way would be to search multiple times and concatenate the results returning a single list. Not as efficient since you are essentially making multiple searches:
IProviderSearchContext searchContext = index.CreateSearchContext();
var items = new List<SearchResultItem>();
var regexResult = SearchRegexHelper.getSearchRegexResult(fulltext);
regexResult.Remove(" ");
foreach (string term in regexResult)
{
var results = searchContext.GetQueryable<SearchResultItem>()
.Where(p => p.Content.Contains(term));
SortSearchResults(results); //results passed in by reference, no need to return object to set it back to itself
items.AddRange(results);
}
NOTE: The above does not take into account duplicates between the result sets.