Many to Many Relationships

[SLY]

I'm trying to figure out how to build this relationship.

Each respite trip is attended by multiple individuals, all of whom bill at a
different rate. How do I join the one trip - to multiple individuals
attending - to multiple billing rates?

 

[pietlinden]

I'm trying to figure out how to build this relationship.

Each respite trip is attended by multiple individuals, all of whom bill at a
different rate. How do I join the one trip - to multiple individuals
attending - to multiple billing rates?

Trip---(1,M)---Attendance---(M,1)---Person

If BillingRate can vary by Trip, then it belongs in Attendance. If
the Person always charges the same rate, it belongs in Person. I'd
bet it belongs in attendance. Or do they have multiple rates per Trip?

 

[SLY]

The billing rate varies by person by trip. So, each person bills differently
than the other participants and differently on each trip. So, it's multiple
rates per trip.

 

[Klatuu]

Then it goes in attendance.
Each record in attendance should show the Trip, the person, the rate, and of
course whatever other info is necessary about the trip.

One other wrinkle. If the trips are repeating, in other words we have
"Bozos on the Bus" trip that happens periodically, then the trip table should
only have all the info specific to the trip. Then your attendance record
should relate to the trip and contain date, time, and other info specific to
the occurance of a trip.