Question

I have the following code that loops through a DataTable and builds another one if certain conditions are met. However, the last row in the initial DataTable is being skipped.

for (int i = 0; i < dt.Rows.Count; i++ )
{
    DataRow row = dt.Rows[i];
    DataRow nextRow = i < dt.Rows.Count - 1 ? dt.Rows[i + 1] : null;

    string account = row[1].ToString();
    string nextAccount = "";
    if (nextRow != null)
    {
        nextAccount = nextRow[1].ToString();
    }

    numberOfItems++;
    totalAmount += Convert.ToDecimal(row[2]);
    row[4] = "D";
    row[5] = c;
    row[6] = Sequence;


    if (nextRow != null && i < dt.Rows.Count && account != nextAccount)
    {
        dt2.Rows.Add("N",
            c,
            row[1],
            row[2],
            row[3],
            numberOfItems,
            totalAmount,
            Sequence);

        numberOfItems = 0;
        totalAmount = 0m;
        Sequence++;
    }

}

In the above code, if I have a table such as:

abc, 1, 2, 3
abc, 1, 2, 5
def, 1, 3, 6

It will process both abc’s, but not def.

dt2 should contain:

abc, 1, 2, 8, 2
def, 1, 3, 6, 1

Where 8 is the total for the 4th column in dt and 2 is the number of abc rows.

I am only getting this though

abc, 1, 2, 8, 2

Answer 1

The problem is with this line:

if (nextRow != null && i < dt.Rows.Count && account != nextAccount) 

Try changing it to

if (account != nextAccount) 

I removed:

nextRow != null

because that prevents the last record from being added.

I also removed:

i < dt.Rows.Count

because that is already enforced by your for loop.

Note: the last row still may not be added if account is the same as the previous row. Not sure what behaviour you wish here.