Error while trying to query the custom list sharepoint 2010

Question

I am trying to query a custom list and getting the following error:

At,

SPListItemCollection OsplistitemCollection = Olist.GetItems(OqueryResponse);

below is my code

string TicketID = "123";
Osite = new SPSite(noPrevSite.ID);
Oweb = Osite.OpenWeb(noPrevWeb.ID);
Olist = Oweb.Lists["ListName"];

helpDeskIDLabel.Text = TicketID;
camlQuery = "<Where><Contains><FieldRef Name='TicketID'/<Value Type='Text'>" 
                      + TicketID+ "</Value></Contains></Where>";
OqueryResponse.Query = camlQuery; 
SPListItemCollection OsplistitemCollection = Olist.GetItems(OqueryResponse);
string count = OsplistitemCollection.Count.ToString();

Update -->ULS Log

Unable to execute query: Error 0x81020014 One or more field types are not installed properly. Go to the list settings page to delete these fields.

Answer 1

You get that error when the fields used in CAML query fields or viewfields are not present in that list. CAML uses the internal name and not the display name. Verify that the ticketid is the internal name of that field and not display name. Go to list settings and click on the field ticketid and observe the url for the param value 'field'. This should match the one used in CAML. It is very likely that someone changed the column's display name after it was created, so the display name would be different from the internal name.

Answer 2

If TicketID is text field and your goal is to get all tickets containing some value then code (written from head!) is:

string TicketId = "123";
using(SPSite oSite = new SPSite(noPrevSite.ID)
{
    using(SPWeb oWeb = oSite.OpenWeb(noPrevWeb.ID))
    {
         SPList oList = oWeb.Lists["ListName"];
         SPQuery query = new SPQuery();
         query.Query = "<Where><Contains><FieldRef Name='TicketID'/><Value Type='Text'>" 
                  + TicketId + "</Value></Contains></Where>";
         SPListItemCollection oSplistitemCollection = oList.GetItems(query);
         string count = oSplistitemCollection.Count.ToString();
    }
}

Also it is not a bad idea to check your list and verify that TicketID is present. However there are other reasons for this query to fail but you need to provide more info and recheck that code you provided is really one you are using (see my comment).