Image Button CommandArgument on GridView

Use the CommandArgument property of an action button on a GridViewRow to facilitate record actions.

<asp:imagebutton commandargument="<%# Bind("RecordGuid")" commandname="EDIT_RECORD" height="12" id="imgEdit" imageurl="~/Images/edit.png" onclick="btnEditRequest_Click" runat="server" tooltip="Edit Request" width="12"></asp:imagebutton>

switch (btn.CommandArgument)
{
   case "EDIT_RECORD":
        break;
   case "DELETE_RECORD":
        break;
   case "VIEW_RECORD":
        if (recordGuid.ToString() != "00000000-0000-0000-0000-000000000000")
        {   
            string url = "NonexpenditureTransferDetail.aspx?id=" + recordGuid.ToString();
            Response.Redirect(url, false);
            Context.ApplicationInstance.CompleteRequest();
        }
        break;
}

Use XQuery to replace Xml element value

DECLARE @newVal varchar(50);
SELECT @newVal = 'A40AA80B-74D3-4357-961E-1A4C9E94651F';
-- Get xml contents
DECLARE @myDoc xml = (SELECT [DATA_XML] FROM [dbo].[TABLE] WHERE ([GUID] = @newVal));

-- Check contents
SELECT @myDoc

-- Replace value of
SET @myDoc.modify('delete (/root/RecordGuid[1])')
SET @myDoc.modify('insert {sql:variable("@newVal")} as first into (/root)[1] ') ;

-- Update record
UPDATE [iMARTDB].[dbo].[TABLE]
SET [DATA_XML] = @myDoc
WHERE ([GUID] = @newVal);

-- Verify
SELECT [DATA_XML] FROM [dbo].[TABLE] WHERE ([GUID] = @newVal);