Use calculated field in Datagrid

[JPimp]

I am not even sure if this is possible, I am pulling in data from a DB, populating 2 text fields, just so I can calculate the difference between the two, and then I want to display the difference in the datagrid. This is what I have so far:

Dim DataReader As OleDbDataReader

        DataGrid1.Visible = True

        Dim myDA As OleDbDataAdapter = New OleDbDataAdapter(cmdSelect)

        Dim myDataSet = New DataSet
        Dim myDataSet2 = New DataSet

        myDA.Fill(myDataSet, "EQ_METER_READING")
        myDA.Fill(myDataSet2, "WO_PM_SCHEDULE")

        Dim Row As DataRow

        If myDataSet.Tables("EQ_METER_READING").Rows.Count > 0 Then

            Row = myDataSet.Tables("EQ_METER_READING").Rows(0)

        End If

        If Row.Item("READING") Is DBNull.Value Then
            READING.Text = String.Empty
        Else
            READING.Text = Row.Item("READING")

        End If

        If myDataSet2.Tables("WO_PM_SCHEDULE").Rows.Count > 0 Then

            Row = myDataSet2.Tables("WO_PM_SCHEDULE").Rows(0)

        End If

        If Row.Item("NEXT_EXE_UNITS") Is DBNull.Value Then
            NEXT_EXE_UNITS.Text = String.Empty
        Else
            NEXT_EXE_UNITS.Text = Row.Item("NEXT_EXE_UNITS")

        End If

        Dim CyclesRemaining As Integer

        CyclesRemaining = (Int32.Parse([NEXT_EXE_UNITS].Text) - Int32.Parse([READING].Text))

        DataGrid1.DataSource = cmdSelect.ExecuteReader

        DataGrid1.DataBind()

Kai-What?

 

[jbenson001]

Is there an error or some question here?
And why would you only display one value in a datagrid? Just display it in a label, literal or textbox.

 

[JPimp]

Yeah, my bad, basically what I want is a column where it shows me the total of this:

CyclesRemaining = (Int32.Parse([NEXT_EXE_UNITS].Text) - Int32.Parse([READING].Text))

What I get in the datagrid is anywhere from 10-100 results and for each row, I would like the product of cyclesremaining showing, I can do it in text boxes, but that would only show me 1st row, unless I somehow loop through the results, but even then it would not be showing directly next to the other results in the datagrid.

Kai-What?

 

[RiverGuy]

Use a Template column in your DataGrid.

 

[JPimp]

I tried the template column, but since my "new" field is a calculated field, it did not like it in the code, but maybe I am doing something wrong??

DataBinding: 'System.Data.Common.DbDataRecord' does not contain a property with the name 'CyclesRemaining'

Is the error I receive from this code:

<asp:TemplateColumn HeaderText="Cyckes Remaining">
						<ItemTemplate>
							<%# DataBinder.Eval(Container.DataItem, "CyclesRemaining") %>
						</ItemTemplate>
					</asp:TemplateColumn>

Kai-What?

 

[RiverGuy]

You need to make a function to do the calculation. Look at this post, it should give you an idea.

http://forums.asp.net/p/786511/786511.aspx

 

[jbenson001]

Calculate what you need to caculate in your SQL statement
If you are just taking columnA and subtracting columnB then it is a very easy sql statemnt.

Select NEXT_EXE_UNITS, READING, NEXT_EXE_UNITS - READING As CyclesRemaining
From YourTable
Where ...etc etc...