The argument types 'Edm.Int16' and 'Edm.String' are incompatible for this operation

Question

I'm facing errors about concatenation of 2 fields with different types within EntityDataSource control.

I've got a dropdownList filled by a EntityDataSource, this ddl displays the Id of each items and I have to modify it to display the concatenation of id + description.

below first definition of the ddl :

    <asp:DropDownList ID="ddlScenarioID" runat="server" AutoPostBack="false" 
        DataSourceID="edsScenarioID" DataTextField="ScenarioID "
        DataValueField="ScenarioID" Height="25px" Width="200px" EnableViewState="true"
        onselectedindexchanged="ddlScenarioID_SelectedIndexChanged" 
        onchange="return ScenarioOnSelectedIndexChange();">
    </asp:DropDownList>

and of the entitydatasource :

<asp:EntityDataSource ID="edsScenarioID" runat="server" 
ConnectionString="name=StressTestEntities" 
DefaultContainerName="StressTestEntities" EnableFlattening="False"
EntitySetName="Scenarios" 
ContextTypeName="BDTTWebConsole.Models.EF.StressTestEntities"
Select="it.[ScenarioID]" OrderBy="it.[ScenarioID] ASC">
</asp:EntityDataSource>

I've tried to add as new DisplayText property as the concatenation of ScenarioId and Description, but it's not working. I've got a error message (see the title of my post )

this the modified code of the entitydatasource

<asp:EntityDataSource ID="edsScenarioID" runat="server" 
ConnectionString="name=StressTestEntities" 
DefaultContainerName="StressTestEntities" EnableFlattening="False"
EntitySetName="Scenarios" 
ContextTypeName="BDTTWebConsole.Models.EF.StressTestEntities"
Select="it.[ScenarioID], it.[ScenarioID]+it.[Description] AS DisplayText " OrderBy="it.   [ScenarioID] ASC">
</asp:EntityDataSource>

Can somebody help me about this? I'm newbie on c# and .net.

thank you

Answer 1

cast(it.[ScenarioID] as System.String)