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Question

I'm building a software for timereporting

I have a Dictionary<string, Dictionary<string, double>>. The key in the main dictionary is a users name and their value is a dictionary of .

I have a function GetDepartment(string UserName) which returns a string with the users department.

What I want is to crate a new dictionary, of the same type, that has the department as the main key and in the subdictionary a where hours is the total for that department.

I have been trying to do this with linq but did not succeed. Would be very glad for some help here!

EDIT: This code does exactly what I want. But I want it in LINQ

 Dictionary<string, Dictionary<string, double>> temphours = new Dictionary<string, Dictionary<string, double>>(); ; foreach (var user in hours) { string department = GetDepartment(user.Key); if (!temphours.ContainsKey(department)) { temphours.Add(department, new Dictionary<string, double>()); } foreach (var customerReport in user.Value) { if (!temphours[department].ContainsKey(customerReport.Key)) { temphours[department].Add(customerReport.Key, 0); } temphours[department][customerReport.Key] += customerReport.Value; } }

Are you sure you are using LINQ to Entities (as your title suggests) and not LINQ to Objects? — Jens
– Jens, Commented Mar 26, 2010 at 11:54
@ jens Fixed the title (mistake by me). @Marcelo: It's a keyvalue pair. A key value pair has a key and a value — Oskar Kjellin
– Oskar Kjellin, Commented Mar 26, 2010 at 12:29

Jens · Accepted Answer · 2010-03-26 12:20:29Z

Why do you want to do this with LINQ? I do not think that it will be any clearer, plus LINQ queries are not as easy to debug.

The following expression will not work in LINQ to Entities, since you cannot call C# function such as GetDepartment there.

Dictionary<string, Dictionary<string, double>> temphours = (from user in hours group user by GetDepartment(user.Key) into department select new { Key = department.Key Value = (from userInDepartment in department from report in userInDepartment.Value group report by report.Key into g // To tired to think of a name =) select new { Key = g.Key Value = g.Sum(reportInG => reportInG.Value) }).ToDictonary(ud => ud.Key, ud=> ud.Value); }).ToDictonary(u => u.Key, u=> u.Value);

I am not sure that this is bug free. At least it should give you an idea on how to do this.

Amy B · Accepted Answer · 2010-03-26 13:57:46Z

Here's my take on it.

Dictionary<string, Dictionary<string, double>> temphours = ( from user in hours let department = GetDepartment(user.Key) from customerReport in user.Value group customerReport by department ) .ToDictionary( g => g.Key, g => g.GroupBy(rep => rep.Key).ToDictionary ( g2 => g2.Key, g2 => g2.Sum(rep => rep.Value) ) );

That's about a direct as I can make it. If you want a little more descriptiveness, then this might do it for you:

Dictionary<string, Dictionary<string, double>> temphours = ( from user in hours let department = GetDepartment(user.Key) from customerReport in user.Value group customerReport by department into reportGroup select new { Department = reportGroup.Key, Reports = ( from report in reportGroup group report.Value by report.Key ).ToDictionary(g => g.Key, g => g.Sum()) } ) .ToDictionary{ x => x.Department, x => x.Reports );

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