Although it is a To-Many, this only has to do with the array being displayed and saved in REST. The database fields exist as a single value.
Much like if the categoryID field was limited to a single value (which can be done in Field Maps), it would still be a To-Many association and an array.
To-Many associations in REST mainly refer to references to other entities (database secondary keys).
Let me know if that clarifies things a bit further!
Bullhorn Enterprise Support Analyst
Thanks for the reply and in the case of Categories there is definitely the potential for it to be a "To-many" relationship. On the lead record there is a purposed field for Client Corporation ID since there can only be one. However, with a Contact it is a "To-many" relationship even though there can only be one? In the UI, you can only choose one, but in the API potentially more associations?
I was just trying to understand why an array is being used if there can only be one. If it is only one, that answers my question but if there is the potential for more than one we need to be aware so the designed integration doesn't break or perform inaccurately if all of the sudden 3 contacts are associated to a lead.
Please confirm that we are sure there can only be one Contact or Candidate per lead and in the other direction, one lead to each Contact or Candidate.
There can only be one Contact or Candidate per Lead and vice versa. It isn't possible via the API or the UI to have more than one in either direction.