I dont have any experience of querying a NoSQL database and i understand theres various ways of querying....using SQL, XQUERY, etc., but id suggest if you have a successful db connection, then the issue is with the command you executed.
Does dynsamodb support SQL? If yes, are you using SQL to query?
Have you tried the simplest query possible? E.g. SELECT * FROM TABLE;
Did you include a fetch in the command you executed?
if this helped answer the post, could you please mark it as 'solved'? Also if you consider whether the title of your post is relevant? Perhaps if the post is solved, it might make sense to update the Subject header field of the post to something more descriptive? This will help people when searching for problems. Ta