Compare Values of two tables

I have a table created out of a XML based web service (Table1 below).
Now after a given time I want to check if the data of that webservice
has changed, so I just call the XML web service again and save that in
another table (Table2 below).

Finally I want to compare the values of these both tables to determine
if there are changes. How can I do that elegantly?

The problem is that attributes method is only working for ONE record
not a whole table. I tried Table1.attributes == Table2.attributes

And in my opinion it is not possible to iterate parallely over two
arrays and compare each value. So is it a good ide to create one array
out of both tables with keys “old” and “new” and compare each old data
with new data?

Like this:

JoinedArray = [{old => {first_ key_and_value_from_table1}, new
=>{first_key_and_value_from_table2}, {old =>
{second_key_and_value_from_table1}, new

JoinedArray.each do |e|
e.old ==

My tables look like this:


id date title comment
1 2003-03-22 whatever good
2 2004-04-23 something bad


id date title comment
10 2003-03-22 whatever good
12 2004-04-23 something bad
27 2005-08-19 anything good

I hope someone can give me a hint. I am completely stuck!