I was busy working on the Amazon Web Services version of my Photo Sharing application (the App Engine version appeared in February 2008). I was able to create a domain with the name friseton.com. I then wrote a simple query against this domain:
select * from friseton.com where email=’dude@example.com’
SimpleDB responded and told me that the select query had an invalid format. On a wild guess, I thought it might be the dot (.) in friseton.com. Sure enough, it was. I deleted the friseton.com domain, added friseton_com, and the query started working.
select * from friseton_com where email=’dude@example.com’
I don’t know if there is any syntax around allowing the dot in the domain name, but I found this, it works, and I’m moving on with the demo. I’ll learn the ins and outs as I go.
Karmic Code Monkey 
#1 by Simple DB Explorer (@sdbexplorer) on July 15, 2012 - 11:05 pm
Domain names need to be enclosed in back-tick quotes if they contains any special characters. Attribute and domain names may appear without quotes if they contain only letters, numbers, underscores (_), or dollar symbols ($) and do not start with a number. You must quote all other attribute and domain names with the backtick (`).