Question

I am trying to group some data without much luck.

I have a list of data

 public class TransactionsViewModel
{
    public string BusinessName { get; set; }
    public string Description { get; set; }
    public int TransactionTypeId { get; set; }
    public string TransactionType { get; set; }

    [Display(Name = "Transaction Amount")]
    public decimal TransactionAmount { get; set; }

    [Display(Name = "Transaction Date")]
    public DateTime TransactionDateTime { get; set; }

}

I am wanting to do some grouping on this so I created a couple of classes like

  public class BusinessTransaction
{
    public string Name { get; set; }
    public List<Transaction> Transactions { get; set; }
}

public class Transaction
{
    public decimal TransactionAmount { get; set; }
    public string Description { get; set; }
    public DateTime TransactionDate { get; set; }
    public string TransactionType { get; set; }

}

So I can group by BusinessName that is simple

  var data = from c in transactions
                   group c by c.BusinessName
                   into business
                   select new BusinessTransaction()
                              {
                                  Name = business.Key,



                              };

How can I group transactions now by TransactionDateTime.Date? I am wanting to send back to the client a data structure like

BusinessName
  28-06-12
     Transaction
     Transaction
   27-06-12
     Transaction
 BusinessName
   28-06-12
      Transaction

Answer 1

I think you want something like:

 var data = from c in transactions
            group c by c.BusinessName
            into business
            select new BusinessTransaction
            {
                Name = business.Key,
                Transactions = business.OrderBy(t => t.TransactionDateTime)
                                       .ToList()
            };

EDIT: That’s all the structure you can support with your current BusinessTransaction class. If you wanted to support the grouping directly, you’d have to add another level of nesting in there.

However, using the existing structure the client can always group things themselves:

foreach (var business in query)
{
    Console.WriteLine(business.Name);
    foreach (var group in business.Transactions
                                  .GroupBy(t => t.TransactionDateTime.Date))
    {
        Console.WriteLine("  {0}", group.Key);
        foreach (var transaction in group)
        {
            Console.WriteLine("    {0}", transaction.Description);
        }
    }
}