Linq查询返回匹配数组中所有单词的行

Question

I need to build a query using linq to return the rows matching all words in an array:

Example array (splitKeywords):

{string[2]}
    [0]: "RENAULT"
    [1]: "CLIO"

KeywordSearch table:

public class KeywordSearch
{
    // Primary properties
    public int Id { get; set; }
    public string Name { get; set; }
    public Keyword Keyword { get; set; }
}

This table has the records:

Id: 1
Name: "RENAULT"
Keyword_Id: 3503

Id: 2
Name: "CLIO"
Keyword_Id: 3503

I want to get all the Keyword_Id s which match all the words in the array.

So far I have:

EDIT:

var keywordSearchQuery = _keywordSearchRepository.Query;

var keywordIds = from k in keywordSearchQuery
                        where splitKeywords.All(word => word.Equals((k.Name)))
                        select k.Keyword.Id;

But It's not working. Any ideas?

Thanks

Answer 1

First you need to combine all of the records with the same Keyword.Id into a single record. Do that with GroupBy.
Once you have them grouped, you can filter out the groups (KeywordIds), where all of the items (the individual records, the names), don't match at least one of the splitKeyWords.

Original - This checks that all Name values match a value in splitKeyWords

var results = keywordSearchQuery
                .GroupBy(k => k.Keyword_Id)
                .Where(g => g.All(k => splitKeyWords.Any(w => w.Equals(k.Name))))
                .Select(g => g.Key);

Updated - This checks that all values in splitKeyWords match a Name.

var results = keywordSearchQuery
                .GroupBy(k => k.Keyword_Id)
                .Where(g => splitKeyWords.All(w => g.Any(k => w.Equals(k.Name))))
                .Select(g => g.Key);

Note that if you have a Keyword.Id with names RENAULT, CLIO, and ASDF, it will match.

Answer 2

This will go through your array and find the matching key for each element, if this is what you're looking for?

var ids splitKeywords.Select(k => keywordSearchQuery.Single(q => q.Name == k).Id).ToArray();

You'd have to do a bit more validation if the Name wasn't unique or if you weren't sure you'd get a match.