I have an Azure topic and want to filter messages on their XML elements.
<stay>
...
</stay>
vs
<flee>
...
</flee>
I have understood the SqlFilter is the way to go, but found no information on how to filter on the presens of an element.
You cannot filter messages based on the payload. SQL Filters work on headers / properties of the message, not message body. A potential way of achieving what you need is to stamp message headers with the appropriate information for SQL Filters to operate on. A few samples available in the official documentation.