[Tutor] design question (Django?)

[Alan Gauld]

Some clarification please.

> (1) Database design. Here are the database tables I think are necessary:
> tblPostalcode: pc6, streetname, nHouseholds, isVisitable, remarks
> tblCollectorSelection: collectorname, streetname, selectiondate

streetname is in both so presumably is the link between collector and 
the postcodes? Can a steetname be in multiple postcodes? So if a 
collector selects a street does he implicitly select multiple post codes?

And

Does a postcode only have a single street? (Ours can have several)

I assume isVisitable is a derived field that you are going to calculate 
each time based on the number of collectors who have selected the 
postcode? If so it may be easier and more efficient to have a mapping 
table to manage the relationship of collectors to postcodes and another 
table for the collector data (although you don't appear to be holding 
much collector data, which surprises me... I assume the users will be 
collectors with login credentials etc?)

As always when modelling data the important information is the 
relationships between the entities and I'm not sure I understand
the relationships between street, postcode and collector.

HTH
-- 
Alan G
Author of the Learn to Program web site
http://www.alan-g.me.uk/