Query the same table three times

[Cathy]

I have a table in MS Access 2003 that ass the following columns

id, date1

This returns around 4000 rows dating back to 2006

I need some guidance on how to
1. query the last 6 months worth of data
2. ensure no duplicates are returned, like when it was inspected multiple
time in the last 6 months
3. add columns - date2, date3
date2 must be the date in the same table, matching the same id, but the
date before date1
date3 must be the date in the same table, matching the same id, but the
date before date2
4. If there is no date3 or 2, then they should be left blank

Effectively showing me each property inspected in the last 6 months, and the
three preceding inspections.

I am not very good with access so would appreciate good instructions on how
to accomplish this

Thanks in advance

C