Purchase Order - Date Change Alert

Hi,

I'm not entirely sure where to start with this - but what I want to achieve is to write a query, and for an alert to be setup to run every day to bring up query results of purchase orders whose delivery dates have changed from what they were on the previous day.

For example

PO # 123 on the 1/1/15 has a delivery date of 30/1/15

On the 7/1/15 the delivery date field is changed to be 28/2/15.

On the 8/1/15 the alert will run this query and bring up PO # 123 with the original delivery date and the new delivery date

Now - I've had a bit of a think about this and I think the answer lies in the change log

I've done a bit of looking around and I believe it requires the ADOC and ADO1 tables - using Object Type 22 and the field loginstanc

However - given my very basic knowledge of SQL and how everything works I'm a little bit out of my depth.

Any help would be greatly appreciated.

Thanks

Rick