So I am looking to achieve something like this:
Table1 [ID Name]
Table2 [ID Name]
Table3 [ID Name]
CategoriesTable [Category ID Name]
CategoriesTable contains a row for every entry in Table1, Table2 and Table3. The category + ID fields are used to identify which table + row is being referenced (but are not foreign keys). e.g
Category ID Name
Subjects 1 Maths
Subjects 2 English
Food 1 Bananas
Materials 1 Steel
What I need to do is update or insert an entry into the CategoriesTable anytime a Row is inserted or updated in Table1, Table2 or Table3. This would be done in DJango with a post_save
signal which could then create/update the associated CategoriesTable row.
I am looking for something similar, but ideally all changes would sit inside 1 transaction. So I imagine some way of building an Ecto.Multi from some registered list of callbacks would be involved.