Hello,

Sorry if this question is already covered somewhere.

I'm using SelfService and need to filter on null values like this:

IPredicateExpression filter = (MessagesFields.MyField == null);

"Null" doesn't work and neither does DBValue.Null.

Any help would be appreciated.

Thanks,

Rick

Have you tried.

IPredicateExpression filter = new PredicateExpression();
filter.Add(MessagesFields.MyField == DBNull.Value);

(MessagesFields.MyField == null) is an IPredicate and not an IPredicateExpression. IPredicateExpressions contain IPredicates.

If you want to shorten your code you can pass an IPredicate in the constructor.

IPredicateExpression filter = new PredicateExpression(MessagesFields.MyField == null == DBNull.Value);

In general avoid 'null' / Nothing in the field comparison predicate constructions with '==' and '!=', use DBNull.Value.