Search based on a set of keywords

Question

I need to make a search based on a set of keywords, that return all the Ads related with those keywords. Then the result is a list of Categories with the Ads Count for each

Answer 1

I think I have a solution now. This is based on your previous question and a few assumptions:

1. Keywords are complete names like "Mercedes-Benz GLK", "Mercedes-Benz Citan".
2. KeywordSearchs are "Mercedes", "Benz" and "GLK" for "Mercedes-Benz GLK" and "Mercedes", "Benz" and "Citan" for "Mercedes-Benz Citan"
3. "Mercedes-Benz GLK" is a "Car", "Mercedes-Benz Citan" is a "Truck"

With those three assumptions in mind I can say that

var keywordIds = from k in keywordSearchQuery
                 where splitKeywords.Contains(k.Name)
                 select k.Keyword.Id;

is the culprit and all queries below rely on it. This query will find all keywords that contain any words in your searchstring.

Example: Given searchstring "Mercedes-Benz GLK" will be split into "Mercedes", "Benz" and "GLK". Your query now finds "Mercedes" and "Benz" in both "Mercedes-Benz GLK" and "Mercedes-Benz Citan".
I think it's obvious that you don't want "Mercedes-Benz GLK" to match "Mercedes-Benz Citan".

The solution is to tell the query to match every splitKeywords with any Keywordsearch and return the appropriate Keyword:

var keywordIds = keywordSearchQuery
                 .GroupBy(k => k.Keyword.Id)
                 .Where(g => splitKeywords.All(w => 
                                               g.Any(k => k.Name.Contains(w))))
                 .Select(g => g.Key);

As for addIds changing it to var addIDs = matchingKac.Select(ad => ad.Ad_Id).Distinct(); should do the trick. Or if matchingKac is only needed in addIds then you could change it to

var matchingKac = (from kac in keywordAdCategoryQuery
                   where keywordIds.Distinct().Contains(kac.Keyword_Id)
                   select kac.Ad_Id).Distinct();

and remove addIds.