So I have to find a matching service for a switch.
I construct the SQL query and pile on the conditions - installed and not ceased and not in the middle of a port, and the right account number and line number and so on.
I get either zero, one, or more results. If I get one, I respond with matching details.
But it not, I have to send a failure. Let's check the failure codes.
iMessage (from which the screen shot comes) copes remarkably well with them.
When a specification casually says to remove accents to compare letters just A to Z, FFS. Ended up scanning the whole Unicode XML file to find A-Z type letters.