Model rework

Opinionated issues of ptf model

Periode

Periode is the table used to hold the relation between Source, and Collections (many-to-many)

With the current design, we cannot reliably know which article/container belongs to which source. In GDML, this can lead to "dangling" articles/issues/containers/collections without any source, and makes fetching the source for one issue or article complicated.

Suggestions :

• Unique key on source / collection pair
• Link Periode to article/container (foreign key ?)

container years

Collection has a fyear/lyear attribute, which is an int. fyear and lyear are updated using django signals.

However, container also a year attribute, which is a str, and can hold a year range (ex : 1987-2021)

Suggestions

• Migrate container.year into container.fyear and container.lyear