creation and update times of elements

[markus2330]

Tasks

To have some auditability, we want:

• creation time (granularity in seconds)
• creation id (person who created)
• modification time (granularity in seconds)
• modification id (person who modified)

Use cases

All layers that have elements, currently:

• for plants see show/edit plant attributes #476
• for drawing layer see Drawing Layer: Backend Implementation #1165

Furthermore, also following should

• map(s) should have above attributes, to be seen in the map list

Not needed:

• seeds are currently private without collaboration

[horenso]

A few comments from @chr-schr and me:

1. We suggest calling it created_at, create_by, modified_at and modified_by since plants.created_at (not plantings) already exists.
   create_by is more descriptive than creation_id in our opinion.

2. We suggest that created_at and modified_at are non-null and are that these have the same value upon creation (like in Windows).

3. For initial values in the migration we propose:

   • map.owner_id for create_by and modified_by
   • map.creation_date for created_at and modified_at

4. Does it make sense to have maps.created_by when there is already an owner_id, meaning would we ever distinguish between creator and owner?
   For maps we suggest:

   • renaming creation_date to created_at and changing the type to timestamp
   • leaving owner_id as it is
   • creating the columns modified_by, modified_at

[markus2330]

1-3: fantastic suggestions, I agree to all of them.

4. no, creator=owner, we need to introduce one term in the glossary and should consistently use that term. Changing to which term is less work?

[horenso]

@markus2330 When should map.modified_by and modified_at change? Whenever any api on the map changed something, right? So when we CUD new planting the map should update map.modified_by and modified_at, shade layer, drawing layer etc.

[markus2330]

Exactly, so some guard needs to be added in every modifying operation. Especially the map date modified date gets modified virtually everywhere a write operation happens.