why some entities in equals(..) use many properties and not only their ID?

[vaughnvernon]

why some entities in equals(..) use many properties and not only their ID?

[gt4dev]

I found answer in IDDD book on page 185.

It allows to identify entities with strategy of 'late identity assignment', before main identity is assigned.
It's VO-like equals. Especially useful in Sets.

[VaughnVernon]

@gt4dev No. It's because the tenantId and productId are a composite id, but not held as one. In a SaaS with multiple tenants all entities must be "striped" with the tenantId. They are separated so the tenant is clearly identified and can be queried on its own.

[gt4dev]

I know, it's just a sample but
as identity is top important in entities let me ask sth.

Generalizing IDDD sample code:
When I 1st time saw Thing with ThingId then I thought that ThingId is just id of thing [common sense]
But it's not (as ID needs TenantId)

From my PoV clearer would be [in saasovation context]

1. either create VO ThingId - which hides all inner elements: id of particular thing + all striping id-s [tenant, product ...] etc
2. or rename ThingId to sth like ThingRawId or ThingUnstripedId - to explicitly express in name that it's not real id

What do think you about it, especially point 1?

IMO with "1"

• model [and code] is simpler
• still you can do all searches for "things" by tenant etc. as is done in current IDDD sample
  It's even more cleared when ID is more complex [like in eg BacklogItem where ID is build from 3 IDs].

BTW
It's late answer, but in the meantime I've been sharpening my DDD skills ;]
Doing study notes https://github.com/gt4dev/study-notes

Your and Evans books are big big changers. Thanks!