Create a FetchXML query that uses ISNULL

Question

I want to make a FetchXML query that is using ISNULL like in SQL query.

In SQL

SELECT * FROM Contact WHERE ISNULL(FirstName, '') = ''

Do they have any operators for it in FetchXML?

Answer 1

Not exactly the same but the below query should give you something to work with.

<fetch mapping="logical">
  <entity name="contact">
    <all-attributes />
    <filter>
      <condition attribute="firstname" operator="null" />
    </filter>
  </entity>
</fetch>