How To Use LINQ To Find Matching Data Against A List Of Strings

Question

Hello,

I have a specialized string dictionary of (string, string) (_RulesAndTheirDescriptions) that contains the name (key) and description (value) of methods in a given class. I currently do the following query to search for a match on the key or value and then bind that to a grid. Works great!

Dim Results = From v In _RulesAndTheirDescriptions _
 Where v.Value.ToString().ToUpper().Contains(Me.txtSearchFor.Text.ToUpper()) _
 Or v.Key.ToString().ToUpper().Contains(Me.txtSearchFor.Text.ToUpper()) _
 Order By v.Key _
 Select New With {.Rule = v.Key, .Description = v.Value.ToString()}

This works great when matching "word" or perhaps even "my word" but I would like to search for "my" and "word" and "also this". Meaning words and phrases seperated by spaces. Much like google and bing. When the user enters a value I only would require that the phrases be quoted. The following RegEx takes care of getting me a list word/phrase the user is looking for. Now I am having a hard time combining the the above query that works with the new enhanced list.

Please excuse the below code. I am just trying to test things and get it working.

Dim b As Match
b = Regex.Match(Me.txtSearchFor.Text, "(?<=(?:^|\s|,)"")[^""]*?(?="")|(?<=\s|^)(?!"")[\w\W]+?(?=\s|$)")

Dim sl As List(Of String) = New List(Of String)

If b.Success Then
    sl.Add(b.Value.ToUpper())

    Dim sMatch = b.NextMatch()

    While sMatch IsNot Nothing AndAlso sMatch.Success
        sl.Add(sMatch.Value.ToUpper())
        sMatch = sMatch.NextMatch()
    End While
End If

Per another post on this site I tried to do the following but that is not returing any results. I suspect because the sl.ToString() returns the type and not the value?

Dim Results = From v In _RulesAndTheirDescriptions _
 Where v.Value.ToString().ToUpper().Contains(sl.ToString()) _
 Order By v.Key _
 Select New With {.Rule = v.Key, .Description = v.Value.ToString()}

If I am going about this all wrong, please enlighten me. Seems like it should be easy.

Thanks in advance, Kevin

Answer 1

Hello You have to have a cross join to solve this problem

Dim Results = From v In _RulesAndTheirDescriptions _
join y in  sl on 1 equals 1 
 Where v.Value.ToString().ToUpper().Contains(y) _
 Order By v.Key _
 Select New With {.Rule = v.Key, .Description = v.Value.ToString()}

This can produce duplicates when more than one token can match a rule.So you can do a distinct if you want unique values

Like  Results.Distinct()