[Solved] Linq where clause in aspx with DateTime does not work

[Sucheta Patil]

Hi
I have a lstCentre in dropdown and txtOnDate as datepicker.
Based on these values the grid should display data.
I am using Linqdatasource with where clause
I tried all the following:
1. Where="Centre == @Centre && ExpectedDate == (DateTime.Parse(@ExpectedDate))"
2. Where="Centre == @Centre && (DateTime.Parse(ExpectedDate)) == @ExpectedDate"
3. Where="Centre == @Centre && ExpectedDate == Convert.ToDateTime(@ExpectedDate)"

None of them work and give me error as shown in screen shot attached.
Below is the code:

Visitors.aspx
******************************************************************
<li>
        <asp:Label ID="lbCentre" runat="server" Text="Centre:" AssociatedControlID="lstCentre"></asp:Label><telerik:RadComboBox ID="lstCentre" runat="server" AppendDataBoundItems="True" DataSourceID="LinqCentre"
            DataTextField="Centre" DataValueField="Centre" DataKeyField="Centre" DataSortField="Centre" ReadOnly="true"
            CausesValidation="False" onselectedindexchanged="lstCentre_SelectedIndexChanged" AutoPostBack="true"><Items><telerik:RadComboBoxItem Text="Choose One..." Value="10" /></Items></telerik:RadComboBox>
        </li><li></li>
        <li><asp:Label ID="lbOnDate" runat="server" Text="On (Date):" AssociatedControlID="txtOnDate"></asp:Label>
            <telerik:RadDatePicker ID="txtOnDate" runat="server" DateFormat="dd/MM/yyyy"
                Enabled="true" Culture="English (United Kingdom)" AutoPostBack="true"
                onselecteddatechanged="txtOnDate_SelectedDateChanged"></telerik:RadDatePicker>
        </li>
 <asp:LinqDataSource ID="LinqVisitors" runat="server"
            ContextTypeName="CWC.Staffnet.Forms.StaffnetDataContext"
            TableName="tblVisitors"
                Where="Centre == @Centre && ExpectedDate == (DateTime.Parse(@ExpectedDate))"
                onselecting="LinqVisitors_Selecting">
            <WhereParameters>
                <asp:ControlParameter ControlID="lstCentre" Name="Centre"
                    PropertyName="SelectedValue" Type="String" />
                <asp:ControlParameter ControlID="txtOnDate" Name="ExpectedDate"
                    PropertyName="SelectedDate" Type="DateTime" />
            </WhereParameters>
        </asp:LinqDataSource>
*****************************************************
Visitors.aspx.cs
*****************************************************
protected void LinqVisitors_Selecting(object sender, LinqDataSourceSelectEventArgs e)
       {
           foreach (KeyValuePair<string, object> kvp in e.WhereParameters)
           {
               if (kvp.Value == null)
               { e.Cancel = true; return; }
           }
       }

Please help me.
Thanks in advance..
S

[Vasil]

Hi Sucheta Patil,

DateTime.Parse(string) method takes as a parameter, string. You are trying to call it with a parameter of type DateTime. Try to set type="string", to your the second control parameter. Or modify the where clause like "ExpectedDate == @ExpectedDate".

All the best,
Vasil
the Telerik team

[Sucheta Patil]

Thanks Vasil,
Changing to String didnt help.
Earlier  I had tried using
Where="Centre == @Centre && ExpectedDate == @ExpectedDate"
Which did not work.
And now all of a sudden  it works!!!
Bit weird.But anyways,
Thanks a ton!!!
S