*Audit_Log* is the right start, and you will also want to involve the *Audit_Properites* table.
*Audit_Log* has a few columns to take note of:
**AU_USER** is a match for your user's ID name.
**AU_ENTITY_TYPE** will tell you the type of item that was modified (bug/defect, requirement, test, cycle, etc).
**AU_ENTITY_ID** will be the ID of the item modified. So if the type above is bug, then you know the **BUG_ID** as it will be a match to the **AU_ENTITY_ID**.
Last to note is the **AU_ACTION_ID** which is the ID given to the modification done.
With the above you can query to narrow it down to your user X based his ID, and only pull any defects that the user modified. And you will have the ID for each bug then.
Next would need to join or cross reference the *AUDIT_Properties* table.
In this table the key columns to note:
**AP_PROPERTY_NAME** will be the name of the field changed.
**AP_OLD_VALUE** is just as it sounds; it is the original value before change.
**AP_NEW_VALUE** is changed new value after change.
**AP_ACTION_ID** is the ID given to the modification and is equal to the **AU_ACTION_ID** from the *Audit_LOG* table.
All you need to do then is compose your query to pull your requested information as needed, using ''**WHERE audit_log.AU_ACTION_ID = audit_properties.AP_ACTION_ID.''**
Hope that helps.