?
Solved

How do you create a new DataTable column expression using a column name and a variable?

Posted on 2006-07-20
4
Medium Priority
?
776 Views
Last Modified: 2008-01-09
How do you create a new DataTable column expression using a columnName * variableName?

The following gives creates a new column, and an expression of MyColumn * (a fixed value)

       ' Create the new column.
        Dim MyNewColumn As New DataColumn
        MyNewColumn.ColumnName = "MyColumnName"
        MyNewColumn.Expression = "AnotherColumnName * 7"

        ' Add column to DataTable
        Me.MyDataSet.MyDataTable.Columns.Add(MyNewColumn)
     
In the above example, I am after the 7 being a variable, not a predetermined fixed value.
0
Comment
Question by:IvanHowarth
  • 2
4 Comments
 
LVL 6

Expert Comment

by:Nandakumar Sakthivel
ID: 17145585
0
 
LVL 19

Accepted Solution

by:
arif_eqbal earned 2000 total points
ID: 17145718
Dim i As Integer = 7
MyNewColumn.Expression = "AnotherColumnName * " & i


0
 
LVL 6

Expert Comment

by:Nandakumar Sakthivel
ID: 17145758

Try this.,

 Dim x As Integer = 9  // assign the value that you want to multiply with the column here

Dim ds As New DataSet
Dim dt As New DataTable
Dim dr As DataRow

Dim column1 As New DataColumn
column1.ColumnName = "Number"
column1.DataType = GetType(Integer)
dt.Columns.Add(column1)

Dim column2 As New DataColumn
column2.ColumnName = "MinValue"
column2.DataType = GetType(Integer)
dt.Columns.Add(column2)

Dim column3 As New DataColumn
column3.ColumnName = "TotalValue"
column3.DataType = GetType(Integer)
column3.Expression = String.Format("Number * {0}", x)
dt.Columns.Add(column3)

dr = dt.NewRow
dr.item(0) = 5
dr.item(1) = 10
dt.Rows.Add(dr)

dr = dt.NewRow
dr.item(0) = 20
dr.item(1) = 30
dt.Rows.Add(dr)

Thanks,
Nanda
0
 

Author Comment

by:IvanHowarth
ID: 17145772
arif_eqbal  answer was exactly what I needed.

Thanks both anyway.
0

Featured Post

Free Tool: Path Explorer

An intuitive utility to help find the CSS path to UI elements on a webpage. These paths are used frequently in a variety of front-end development and QA automation tasks.

One of a set of tools we're offering as a way of saying thank you for being a part of the community.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

Join & Write a Comment

I think the Typed DataTable and Typed DataSet are very good options when working with data, but I don't like auto-generated code. First, I create an Abstract Class for my DataTables Common Code.  This class Inherits from DataTable. Also, it can …
If you need to start windows update installation remotely or as a scheduled task you will find this very helpful.
To export Lotus Notes to Outlook PST or Exchange and Domino Server files to Exchange Server or PST files with ease, go for Kernel for Lotus Notes to Outlook conversion tool. Through the video, you can watch the conversion process. A common user with…
Watch the software video of Kernel Import PST to Office 365 tools which can easily import PST and OST files to Office 365 for bulk mailboxes. The process of migration is simple and user can map source and destination mailboxes and easily import data…

584 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question