Question

I am new to working with C# and databases.

I need to iterate over a Datatable (contained in a dataset) when I am iterating, I might need to compare the values from the current row with those from the previous row or next row.

I am currently iterating like this:

 foreach(DataRow dr in ds.Tables["Invoices"].Rows)
 {
     //Check if invoice id is equal to invoice id from previous/next row

 }

One way I can think of is to maintain “prev” variables to store the old value and compare and update as go along but I wanted to see if the DataTable offered any built in options.

Thanks,
Calvin

Answer 1

for( int i = 0; i < ds.Tables["Invoices"].Rows.Count; i++ )
{
    if( i > 0 )
    {
       // Compare with previous row using index
       if( ds.Tables["Invoices"].Rows[i]["Amount"] > ds.Tables["Invoices"].Rows[i - 1]["Amount"])
       {}
    }
    if( i < ds.Tables["Invoices"].Rows.Count - 1 )
    {
        if( ds.Tables["Invoices"].Rows[i]["Amount"] > ds.Tables["Invoices"].Rows[i + 1]["Amount"])
        {}
    }
}