Discussion: Should domain API take primary key as an argument or the entire record?

[saurabhnanda]

should functions like activateTenant or editProduct take a TenantID or ProductID as input OR Tenant or Product

[jfoutz]

Tenant vs TenantID, Requiring a Tenant seems to indicate a select before an update. the Tenant record needs to be populated, then modified based on the query params, then finally sent back across the domain API for an update. You can say semantics indicate the Tenant record is just the differences between what's in the db and the current object, so just update the populated fields. That approach seems confusing for insert though. I like ID, but i'd like to see a slick alternative.

[wz1000]

The semantics of those are quite different. A Tenant is a pure Haskell value, while a TenantId is a reference to a mutable resource. This distinction makes which to use when quite clear. If you are only performing pure transformations to a value, then Tenant should be used. Otherwise you need TenantId