How I Can Filter a Datatable?
I Use a Datatable with Information About Users and I Want Search a User or a List of Users in This Datatable. I Try It Butit Don't Work: ( Here Is My C# Code...
I use a DataTable with Information about Users and I want search a user or a list of users in this DataTable. I try it butit don't work :(
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;
}
7 Answers
You can use DataView.
DataView dv = new DataView(yourDatatable);
dv.RowFilter = "query"; // query example = "id = 10"
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).
use it:
.CopyToDataTable()
example:
string _sqlWhere = "Nachname = 'test'";
string _sqlOrder = "Nachname DESC";
DataTable _newDataTable = yurDateTable.Select(_sqlWhere, _sqlOrder).CopyToDataTable();
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
Hope someone will find that is useful
For anybody who work in VB.NET (just in case)
Dim dv As DataView = yourDatatable.DefaultView
dv.RowFilter ="query" ' ex: "parentid = 0"
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
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>();
}
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
