I need to collect registered orders from a table named OrdersOn the last 30 days.
In your query, use the expression SomData() ( or DateAdd() in Access) as the criteria in the date following form:
SomData()
DateAdd()
>= SomData("d"; -30; Data() )
It makes a WHERE of the field returning all the dates of the last 30 days. Field type must be Data
WHERE
Data