How to loop thru the data table

[njahnavi]

Hi I am using vb.net version 2.0

I have a datatable in the dataset.
The data table is "Employee table"
The data table contains "Employeename " field.
I want to loop thru the Employee table like once for each employee since i may have many rows for each employee..

How can i use for each statement for a data table...

I am very new to vb ..

Any help is greately appreciated.

 

[njahnavi]

I have a table adapter in the dataset not the datatable...

 

[RiverGuy]

To loop through the DataRows of a DataTable, do the following:

For Each dr As DataRow In YourDatatable.Rows
  MessageBox.Show(dr.Item("SomeColumnName").ToString())
Next

 

[Andrzejek]

If your datatable is created based on the SQL that ends with: "ORDER By Employeename", you may do:

[blue]Dim strEmplName As String[/blue]
For Each dr As DataRow In YourDatatable.Rows
  [blue]If strEmplName <> dr.Item("Employeename").ToString() Then[/blue]
    MessageBox.Show(dr.Item("Employeename").ToString())
    [blue]strEmplName = dr.Item("Employeename").ToString() 
  End If[/blue]
Next

Have fun.

---- Andy

 

[Sorwen]

One thing I would add is if have not pulled the DataTable from the DataSet you could do so like:

Dim CurrentDT As New DataTable = YourDataSet.("TableName")
For Each dr As DataRow In CurrentDT.Rows

or

For Each dr As DataRow In YourDataSet("TableName").Rows

-I hate Microsoft!
-Forever and always forward.
-My kingdom for a edit button!

 

[njahnavi]

actually i was looking for something which mimics

select distinct employee from emp table

can we do that using vb.net
"for each employee in emp table"...
some thing like that...

I greatly appreciate your support.

 

[RiverGuy]

Why don't you just fill a DataTable from the database with a list of employees?

 

[njahnavi]

may be i can do that..however our company has some regulations so they just give us acess to the dataset in the vb.net not to the actual database..soem security reasons..

I know it would be quite easy to write a stored procedure..however i was wondering what can i do for the same fucntionality in the vb.

 

[RiverGuy]

I would ask the person in charge to let you have an Employee dataset. I never like having to work around the best process and end up with a less efficient application. However, if you cannot do that, here is one way to get a table of just employees. You might check out LINQ to see if you can do something more efficiently there.

Dim Employees As DataTable = New DataTable
Employees.TableName = "Employees"
Employees.Columns.Add("EmployeeName", System.Type.GetType("System.String"))

For Each dr As DataRow In YourDataTable.Rows
        If Employees.Select("EmployeeName = '" & dr.Item("EmployeeName") & "'").length = 0 Then
            Dim NewRow As DataRow = Employees.NewRow
            NewRow.Item("EmployeeName") = dr.item("EmployeeName")
            Employees.Rows.Add(NewRow)
        End If
Next

        For Each EmployeeRow As DataRow In Employees.Rows
            'Do something with each employee
        Next

 

[jebenson]

Unfortunately, the DataTable.Select method does not accept DISTINCT. I found this method to do this though:

http://weblogs.asp.net/eporter/archive/2005/02/10/370548.aspx

It might be a bit slow if you have a large amount of data; I haven't actually tested it.


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