query to show gaps in a date field

[Lockrin]

Hello all. I have a database that tracks certifications for welders. I have a table [Welder Maintenance] which has fields [Clock Number] [Process Name] and [Date]. I need to know for each unique record of clock number and process name if there is a gap of time of more than 3 months that there is no record for. I am also thinking about possibly adding a yes/no field something like [Weld Test]. If the welder has not welded in 3 months he is no longer certified, however if he takes a test he will be certified again and keeps his certification for 3 months from the last time that he welds something.



So basically I need to set up a query that shows me any gap in dates of more than 3 months but it is reset if there is a record checked yes. Any ideas?

[TheShabz]

look up the datediff() function and see if it works for you