Question: I am trying to understand the dataset and how I can use it. It looks like a really powerful feature but it has an incredible amount of objects. It seems to me that I should be able to do simple things like create and edit values. But for the life of me I can’t seem to figure out how it works. Do you have some simple example that show how you can create a dataset and then update the individual rows?
Answer: Sure – here are some examples.
- The following creates a dataset that we can use in the later examples.
' create the item table
Dim tblitem As DataTable = New DataTable("item")
Dim itemid As DataColumn = New DataColumn("itemno", _ Type.GetType("System.Int32"))
Dim colititle As DataColumn = New DataColumn("title", _ Type.GetType("System.String"))
Dim colipubdate As DataColumn = New DataColumn("pubdate", _ Type.GetType("System.String"))
Dim colidesc As DataColumn = New DataColumn("description", _ Type.GetType("System.String"))
Dim colilink As DataColumn = New DataColumn("link", _ Type.GetType("System.String"))
‘ create the columns
tblitem.Columns.Add(itemid)
tblitem.Columns.Add(colititle)
tblitem.Columns.Add(colipubdate)
tblitem.Columns.Add(colidesc)
tblitem.Columns.Add(colilink)
‘ add it to the dataset
ds.Tables.Add(tblitem)
- Create a datatable from the dataset and insert a datarow.
Dim dt As DataTable = ds.Tables("item")
' get the datarow
Dim dtrow As DataRow
dtrow = dt.NewRow()
dtrow("itemno") = 10
dtrow("link") = "http://www.msn.com"
dt.Rows.Add(dtrow)
- Select the new row and edit the value
Dim dr As DataRow() = dt.Select("itemno=10")
If dr.Length > 0 Then
dr(0).Item("link") = "http://www.test.com"
End If
dt.AcceptChanges()
11:00:34 PM
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