How limit works? limit 1 does not return anything

I am working through training n1ql material, support limit 1 will return one document for couchmusic1.userprofile, if I don’t set any limit, it will return lot of results but it doesn’t return any results if I set limit 1. here is the query:
select * from couchmusic1.userprofile limit 1;

Sorry about that. Please do the following:

SELECT userprofile
FROM couchmusic1
WHERE userprofile IS NOT NULL

We are aware of the problem and will update the training material.