After re-reading Chapter 5, as Paul suggested in another topic, I believe I've dispelled my confusion.
Hash: a variable that has exactly two columns and (potentially) many rows of data
The hash itself is the variable.
The two COLUMNS are: 1)the keys and 2)their associated values.
So 'ID' is a key. 'name' is a key. 'country' is a key. etc.
Each set of key and value is a row. There can be many, many key/value combinations, but there is ever only one column of keys and one column of values.
(I had been incorrectly picturing the keys in the Page 162 problem as columns across the top of a sql table: ID as one column, name as another, country as a third, etc.)
Slow...but I finally get there.
This post has been edited by lab999: 23 August 2010 - 12:10 PM