Let's say we have a DataTable in which their is a column of age. We need to select the person whose age is the older one. The below code will do
Public Function GetData() As DataTable
Dim dt As New DataTable()
'Add some columns
dt.Columns.Add(New DataColumn("Age", GetType(Int32)))
'Add some rows
'First Row
Dim row1 As DataRow = dt.NewRow()
row1("Age") = 21
'Second Row
Dim row2 As DataRow = dt.NewRow()
row2("Age") = 11
'Third Row
Dim row3 As DataRow = dt.NewRow()
row3("Age") = 12
'Fourth Row
Dim row4 As DataRow = dt.NewRow()
row4("Age") = 55
'Fifth Row
Dim row5 As DataRow = dt.NewRow()
row5("Age") = 18
'Add the rows to the table
dt.Rows.Add(row1)
dt.Rows.Add(row2)
dt.Rows.Add(row3)
dt.Rows.Add(row4)
dt.Rows.Add(row5)
'return the table
Return dt
End Function
Then filter as under
Dim oldestRecord = GetData().AsEnumerable().[Select](Function(dr) dr("Age")).Max()