CODEWITHSUNDEEP
c#.netfilterdatatabledataset
Tarasov
Tarasov

Reputation: 3683

How I can filter a Datatable by name?

I have a DataTable with information about users and I want to search for a user or a list of users in this DataTable.

Here is my C# code:

public DataTable GetEntriesBySearch(string username,string location,DataTable table)
{
    list = null;
    list = table;

    string expression;
    string sortOrder;

    expression = "Nachname = 'test'";
    sortOrder = "nachname DESC";

    DataRow[] rows =  list.Select(expression, sortOrder);

    list = null; // for testing
    list = new DataTable(); // for testing

    foreach (DataRow row in rows)
    {
        list.ImportRow(row);
    }

    return list; 
}

Upvotes: 95

Views: 437462

Answers (7)

AshkaliD
AshkaliD

Reputation: 299

Sometimes you actually want to return a DataTable than a DataView. So a DataView was not good in my case and I guess few others would want that too. Here is what I used to do

myDataTable.select("myquery").CopyToDataTable()

This will filter myDataTable which is a DataTable and return a new DataTable

Upvotes: 14

VolkanCetinkaya
VolkanCetinkaya

Reputation: 699

use it:

.CopyToDataTable()

example:

string _sqlWhere = "Nachname = 'test'";
string _sqlOrder = "Nachname DESC";

DataTable _newDataTable = yurDataTable.Select(_sqlWhere, _sqlOrder).CopyToDataTable();

Upvotes: 24

Santosh Kumar
Santosh Kumar

Reputation: 69

Hi we can use ToLower Method sometimes it is not filter.

EmployeeId = Session["EmployeeID"].ToString();
var rows = dtCrewList.AsEnumerable().Where
   (row => row.Field<string>("EmployeeId").ToLower()== EmployeeId.ToLower());

   if (rows.Any())
   {
        tblFiltered = rows.CopyToDataTable<DataRow>();
   }

Upvotes: 2

Tim Schmelter
Tim Schmelter

Reputation: 460058

If you're using at least .NET 3.5, i would suggest to use Linq-To-DataTable instead since it's much more readable and powerful:

DataTable tblFiltered = table.AsEnumerable()
          .Where(row => row.Field<String>("Nachname") == username
                   &&   row.Field<String>("Ort") == location)
          .OrderByDescending(row => row.Field<String>("Nachname"))
          .CopyToDataTable();

Above code is just an example, actually you have many more methods available.

Remember to add using System.Linq; and for the AsEnumerable extension method a reference to the System.Data.DataSetExtensions dll (How).

Upvotes: 144

nghiavt
nghiavt

Reputation: 443

For anybody who work in VB.NET (just in case)

Dim dv As DataView = yourDatatable.DefaultView

dv.RowFilter ="query" ' ex: "parentid = 0"

Upvotes: 11

Kadir
Kadir

Reputation: 3214

You can use DataView.

DataView dv = new DataView(yourDatatable);
dv.RowFilter = "query"; // query example = "id = 10"


http://www.csharp-examples.net/dataview-rowfilter/

Upvotes: 153

Maxim Kornilov
Maxim Kornilov

Reputation: 6055

It is better to use DataView for this task.

Example of the using it you can find in this post: How to filter data in dataview

Upvotes: 5

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