根据条件丢弃SQL结果行

Question

I have the following data:

Ord_Act_Deliv_DateTime  TrmnlGrp_Key    Ord_CustLoc_Key Ord_Driver_Key     Ord_Inv_No    Credits
2016-04-01 11:00:00     3               429             93                 INV-00055295  True
2016-04-01 11:00:00     3               135             93                 INV-00055295A False
2016-04-01 11:00:00     3               429             93                 INV-00055295C False

what I'm trying to accomplish is as follows

if credits = true
set @temp_invoice_no = Ord_inv_No + 'C'

SELECT * FROM Orders WHERE Ord_Inv_No NOT IN (original inv no with credit, inv no + 'C')

I may have many records like these in my selected date range and I need to make sure the original and credit do not make it into the final result set. From my research so far, it looks like most suggest CASE for simple comparisons (which I don't think this can fit that situation) or IF designating seperate select statements with a variable that is passed or declared in the statement. Maybe I'm misunderstanding the capabilities of CASE and IF. Please help, I'm stuck.

I can also explore doing this in C#, but I'm still fairly green there. I've got the result in a DataTable but evaluating the table is not something I've figured out how to do other than to throw each row to a string.

Answer 1

So, you've got a set of records where the columns to focus on are Ord_Inv_No and Credits .

That first bit, you're setting a temporary variable with which you don't seem to be doing anything.

As for the select query

 SELECT * FROM Orders WHERE Ord_Inv_No NOT IN (original inv no with credit, inv no + 'C')

The only distinguishing thing I see in original inv no with credit, inv no + 'C' is that it's Credits column value is set to True (from the first bit). If that's the case, this query should work for you:

SELECT * FROM Orders WHERE Credits=true

Answer 2

I ended up doing the following in C#:

 foreach(DataRow row in results.Rows)
        {
            credit = Convert.ToBoolean(row["Credits"].ToString());
            if(credit)
            {
                if (String.IsNullOrWhiteSpace(selectString))
                {
                    tempString = row["Ord_Inv_No"].ToString();
                    selectString = String.Format("'{0}', '{0}C'",tempString);
                }
                else
                {
                    tempString = row["Ord_Inv_No"].ToString();
                    selectString += String.Format(", '{0}', '{0}C'", tempString);
                }

            }
        }

        // The following three lines are for troubleshooting, shows the items being selected out and the initial count.
        // If DriverKey is 9 and dates are 5-2-16 - 5-8-16 String should show to INV numbers and count should be 19
        if (!String.IsNullOrWhiteSpace(selectString))
            MessageBox.Show(selectString);
        MessageBox.Show(results.Rows.Count.ToString());
        // only process if string is not empty, need code

        if (!String.IsNullOrWhiteSpace(selectString))
        {
            try
            {
                var rows = results.Select("Ord_Inv_No IN (" + selectString + ")");
                foreach (var row in rows)
                    row.Delete();
                results.AcceptChanges();
                // This is for troubleshooting, gets the final number of rows after edits 
                // If DriverKey is 9 and dates are 5-2-16 - 5-8-16 final count should be 17
                MessageBox.Show(results.Rows.Count.ToString());
                results.Columns.Remove("Credits");
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.ToString());
            }