CODEWITHSUNDEEP
c#linqlambda
user1078749
user1078749

Reputation: 263

Group By using more than two columns by Lambda expression

I have to convert my given linq query in lambda expression. i.e.

var scholars = (from scholar in db.Scholars
                join suspension in db.Suspensions 
                    on scholar.ID equals suspension.ScholarID

                where suspension.StartDate >= startDate && 
                      suspension.EndDate <= endDate

                group scholar by new { scholar.ID, scholar.FirstName, scholar.LastName }
                    into g

                select new
                {
                    FullName = g.Key.FirstName +" " + g.Key.LastName,
                    TotalSuspensionSum = g.Sum(x => x.Suspensions.Sum(y => y.SuspensionDays))
                })
                .ToList()
                .OrderBy(x=> x.FullName);

Upvotes: 3

Views: 35451

Answers (2)

Amir Sherafatian
Amir Sherafatian

Reputation: 2083

this is your lambda:

var scholars = db.Scholars.Join(db.Suspensions,
        scholar => scholar.ID,
        suspension => suspension.ScholarID,
        (scholar, suspension) => new {scholar, suspension})
    .Where(u => u.suspension.StartDate >= startDate && 
                u.suspension.EndDate <= endDate)
    .GroupBy(u => new { u.scholar.ID, u.scholar.FirstName, u.scholar.LastName })
    .Select(u => new 
        {
            FullName = u.Key.FirstName + " " + u.Key.LastName,
            TotalSuspensionSum = u.Sum(x => 
                x.scholar.Suspensions.Sum(y => y.SuspensionDays)
            )
        })
    .OrderBy(x => x.FullName)
    .ToList();

Upvotes: 17

Ashley Medway
Ashley Medway

Reputation: 7301

Well I don't think I should do all your work for you but specifically the group by you are asking about could be done like:

...GroupBy(x => new { x.ID, x.FirstName, x.LastName })...

Upvotes: 7

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