Continuing with the spirit of using the Stack Exchange Data Explorer to learn SQL, (see: Can we become our own “Northwind” for teaching SQL / databases?), I've decided to try to write a query to answer a simple question (on meta): What % of stackoverflow users have over 10,000 rep?.

Here's what I've done:

Query#1

SELECT COUNT(*)
FROM Users
WHERE
  Users.Reputation >= 10000

Result:

556

Query#2

SELECT COUNT(*)
FROM
  USERS

Result:

227691

Now, how do I put them together into one query? What is this query idiom called? What do I need to write so I can get, say, a one-row three-column result like this:

556     227691      0,00244190592