Linq query for SortedList with inner List

Question

I have a sorted list defined in this way

SortedList

 

<COInfo, List<GlobalInfo>> COInfoList;

CoInfo is a object which holds company info. Key col is Company Name..

GlobalInfo is a object which is having cols like Nationality, Language Code..

I want to run a query which can return

Language code (i.e. En, Ar, etc..)

Where Company Name is the passed company name
and Nationality is a particular nationality..

The one where clause is on the key element of sorted list and other is on the value element of sorted list..

I tried various options like below but none of them is working..

var

 

Temp = from CO in COInfoList

 

where CO.Key.Company == Company

 

select CO.Value.Where( o => o.Nationality == FiltValue).Single().LangCode.ToString();

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IMP : There might be a delay in posting replies due to time difference (GMT +2:00) and Friday's Holiday instead of Sunday.

Answer 1

By "none of them is working" you mean no results are returned? Or is an error being thrown? You might be running into a case-sensitivity issue since you're using == to compare the string values for Company and FiltValue. If the company you're searching for is "Microsoft" but you pass in a lower case "microsoft" then it will not match. Same thing for FiltValue.

So either ensure you're passing in the correct value, with matching case, or perform a case insensitive comparison, such as:

var query = from CO in COInfoList
            where CO.Key.Company.Equals(Company, StringComparison.InvariantCultureIgnoreCase)
            select CO.Value.Where(o => o.Nationality.Equals(FiltValue, StringComparison.InvariantCultureIgnoreCase))
                            .Single().LangCode.ToString();

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Document my code? Why do you think it's called "code"?

Answer 2

Sorry my post was incomplete, it is giving me a err.. with this query i was hoping that i will get a string as a result but instead i'm getting a collection back.. and this is the error i'm getting..

Error 1 Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<string>' to 'string'

i simply want a correct query which can return me langcode as a string of a passed company and passed nationality from the sorted list..

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IMP : There might be a delay in posting replies due to time difference (GMT +2:00) and Friday's Holiday instead of Sunday.

Answer 3

How is LangCode declared in the GlobalInfo class? Can it have multiple codes per Nationality? Can you provide a small working sample of the SortedList?

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Document my code? Why do you think it's called "code"?

Answer 4

Langcode is enum.. this is how it is being filled..

List

 

<GlobalInfo> GlobalInfoList = new List<GlobalInfo>()

{

 

new GlobalInfo() {Nationality = "BANGLADESHI", LangCode = SupportedLanguages.Bn},

 

new GlobalInfo() {Nationality = "JORDANIAN", LangCode = SupportedLanguages.Ar},

 

new GlobalInfo() {Nationality = "SRILANKAN", LangCode = SupportedLanguages.Si}

};

this is how CoInfoList is getting filled..

COInfoList =

new SortedList<COInfo, List<GlobalInfo>>()

{

{

new COInfo() {Company = "MYCOMP", Currency = "USD"}, GlobalInfoList}

};

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IMP : There might be a delay in posting replies due to time difference (GMT +2:00) and Friday's Holiday instead of Sunday.

Answer 5

Sorry my post was incomplete, it is giving me a err.. with this query i was hoping that i will get a string as a result but instead i'm getting a collection back.. and this is the error i'm getting..

Error 1 Cannot implicitly convert type 'System.Collections.Generic.IEnumerable<string>' to 'string'

i simply want a correct query which can return me langcode as a string of a passed company and passed nationality from the sorted list..

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IMP : There might be a delay in posting replies due to time difference (GMT +2:00) and Friday's Holiday instead of Sunday.

You are likely getting this error because the query returns an IEnumerable<string> and you're trying to assign it to a string variable. That assignment isn't shown in your code above.

Using the same query I gave earlier, you would get that error if you wrote:

string result = query;

However, since it's a collection you need to use Single() to return the value from the sequence:

string result = query.Single();

Note that you should consider using SingleOrDefault() in the original query and the result in case your filter returns no results, otherwise an exception will be thrown.

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Document my code? Why do you think it's called "code"?

Answer 6

Kindly note i'm already using single but result is same. it is the same query which i have given before except you can change var to string, it is not working, this is what is my question that why this is not returning a single element when i'm giving it already..

string Temp = from CO in COInfoList

 

 

where CO.Key.Company == Company

 

 

select CO.Value.Where( o => o.Nationality == FiltValue).Single().LangCode.ToString();

 

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IMP : There might be a delay

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IMP : There might be a delay in posting replies due to time difference (GMT +2:00) and Friday's Holiday instead of Sunday.

Answer 7

I meant that a second call to Single() is needed to get the actual string value. Here's how the query looks:

    var originalQuery = from CO in COInfoList
            where CO.Key.Company.Equals(Company, StringComparison.InvariantCultureIgnoreCase)
            select CO.Value.Where(o => o.Nationality.Equals(FiltValue, StringComparison.InvariantCultureIgnoreCase))
                            .Single().LangCode.ToString();

Analyzing the last line,  the Single() call returns the GlobalInfo item that matched the whole filtration process, returning an IEnumerable<GlobalInfo> with 1 item. The LangCode call returns an IEnumerable<SupportedLanguages>. Finally, the ToString() call returns an IEnumerable<string>. In all these cases you have 1 item in an IEnumerable collection. It seems somewhat odd, but in order to access it, you can call Single() once again:

    var originalQuery = from CO in COInfoList
            where CO.Key.Company.Equals(Company, StringComparison.InvariantCultureIgnoreCase)
            select CO.Value.Where(o => o.Nationality.Equals(FiltValue, StringComparison.InvariantCultureIgnoreCase))
                            .Single().LangCode.ToString();
	string result = originalQuery.Single();

Does that address your question?

Another way to write this query that might be less confusing is to use SelectMany to flatten the nested collections:

string langCode = (from CO in COInfoList
       where CO.Key.Company.Equals(Company, StringComparison.InvariantCultureIgnoreCase)
       from i in CO.Value
       where i.Nationality.Equals(FiltValue, StringComparison.InvariantCultureIgnoreCase)
       select i.LangCode).Single().ToString();
langCode.Dump();

string langCode2 = COInfoList.Where(CO => CO.Key.Company.Equals(Company, StringComparison.InvariantCultureIgnoreCase))
                 .SelectMany(CO => CO.Value, (CO, i) => new { CO = CO, i = i })
                 .Where(o => o.i.Nationality.Equals(FiltValue, StringComparison.InvariantCultureIgnoreCase))
                 .Select(o => o.i.LangCode)
                 .Single().ToString();

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Document my code? Why do you think it's called "code"?