Question

I have a linq query to locate a matching item in a SharePoint library. It works fine if there is a custom property called ‘MMSTerm’ but if the property is null then obviously my string modifications will fail and error out when it hits x[“MMSTerm”]

I will need to use string.replace in my where operation so a null won’t be good.

SPListItem item = (from x in Items.OfType<SPListItem>()
                where x["MMSTerm"].ToString() == pageReference.ToString()
                select x).ToList<SPListItem>().FirstOrDefault();

Hopefully this is an easy one.

Answer 1

You can verify if field exists with SPFieldCollection.ContainsField method

SPListItem item = (from x in Items.OfType<SPListItem>()
                   where x.Fields.ContainsField("MMSTerm") && 
                         (x["MMSTerm"] == null ||
                          x["MMSTerm"].ToString() == pageReference.ToString())
                   select x).FirstOrDefault();

Also I think fluent API looks better in this case:

SPListItem item = Items.OfType<SPListItem>()
                       .FirstOrDefault(x => 
                           x.Fields.ContainsField("MMSTerm") &&
                          (x["MMSTerm"] == null ||
                           x["MMSTerm"].ToString() == pageReference.ToString()));