Remove From My Forums

Error when to create column

Question

User-373571997 posted


            try
            {
                var query = (from b in base.MyEntities.shipmentsamples
                             group b by b.color into bGroup
                             select new { color = bGroup.Key, Data = bGroup, Total = bGroup.Sum(z => z.qty) });

                var grandTotal = base.MyEntities.shipmentsamples.Sum(d => d.qty);
                result = new DataTable();

                foreach (var itm in query.ToList())
                {
                    var sizeTotal = itm.Data.Sum(c => c.qty);
                    foreach (var itm2 in itm.Data)
                    {
                        result.Columns.Add("ID", typeof(Int32));
                        result.Columns.Add("Color", typeof(Int32));
                        result.Columns.Add(itm2.size.ToString(), typeof(Int32));
                    }
                }

guy this is my coding , i want to ask  how i can avoid when i looping ?

Tuesday, October 11, 2011 11:53 PM

Answers

0

Sign in to vote
User3866881 posted

Hello:)

According to my experience, I think there's something wrong with your logic——

foreach (var itm2 in itm.Data)
{
result.Columns.Add("ID", typeof(Int32));
result.Columns.Add("Color", typeof(Int32));
result.Columns.Add(itm2.size.ToString(), typeof(Int32));
}

If you write foreach there, I'm afraid you'll create duplicated columns for the DataTable, and the whole solution should be it that you should create a DataTable schema first, and then use a foreach to loop and assign values to the DataTable：

result = new DataTable();

result.Columns.Add("ID", typeof(Int32));
result.Columns.Add("Color", typeof(Int32));
result.Columns.Add("Size",typeof(Int32));

foreach (var itm in query.ToList())
                {
                    var sizeTotal = itm.Data.Sum(c => c.qty);
                    foreach (var itm2 in itm.Data)
                    {
                        result.Rows.Add(itm2.Id,itm.Color,sizeTotal);
                    }
                }
- Marked as answer by Anonymous Thursday, October 7, 2021 12:00 AM
Thursday, October 13, 2011 9:24 PM

Answered by:

Error when to create column

Question

Answers