Working with DataTables and Efficiency

Question

I have a couple of questions regarding efficiency and performance. I appreciate your advise on this.

Question 1:
I am using LINQ. 'GetEntityList' is a stored procedure I am calling, and the result is an object that holds what the stored procedure returns.
'The code works perfect, but is that an efficient way to convert an enumerable object to a datatable? I just want to make sure I am on the right track.

        Dim Result = db.GetEntityList()
        Dim resultList As List(Of GetEntityListResult) = Result.ToList
        Dim dt As New DataTable

        dt.Columns.Add("GenEntNumber")
        dt.Columns.Add("GenEntName")
        dt.Columns.Add("ComLegalName")
      
 Dim dr As DataRow
        For Each item As GetEntityListResult In resultList

            dr = dt.NewRow()
            dr(0) = item.GenEntNumber
            dr(1) = item.GenEntName
            dr(2) = item.ComLegalName
            dt.Rows.Add(dr)
        Next

 Question 2:         
The following is a peice of code that filters 'MainDataTable' and creates a new datatable with the filtered Data. The code works perfect, but I am wondering if my code is efficient?

            Dim filteredTable As New DataTable
            filteredTable.Columns.Add("TravCategory")
            filteredTable.Columns.Add("TravCompany")
            filteredTable.Columns.Add("TravAgency")
           
 For Each DataRow In MainDataTable.Select("TravCategory='category1'")
                    dr = filteredTable.NewRow()
                    dr(0) = DataRow(0)
                    dr(1) = DataRow(1)
                    dr(2) = DataRow(2)
                  
                    filteredTable.Rows.Add(dr)

                Next

Answer 1

Question 1:

Yes, this is fine.  The one potential improvement I see here would be to just avoid calling:

      Dim resultList As List(Of GetEntityListResult) = Result.ToList

There is no reason to create the list in this case.  Just do your foreach on Result directly, so you never create the List.

Question 2:

This looks very reasonable, and reasonably efficient.

---

Reed Copsey, Jr. - http://reedcopsey.com