For my small business, I have three levels of information I'm trying to manage. I have (a) the human client, (b) their pet, and (c) the services that they want for their pet. Each human can have multiple pets, and each pet can have multiple services. The projects themselves occur at the pet level, since one human might come back multiple times with different pets, and all the services for a pet occur at once. A pet will not come back for more services again in the future, so it makes sense that we could consider "pet" to be the main unit of analysis (sorry, I'm a social scientist by training, forgive my lingo). A big part of my work is thinking about how I complete tasks by what services I need to do in any given day; in other words, Spot might need Service A, Service B, and Service C done, and I care about knowing what services I've already done and what I still need to do for Spot. Although Service A is always "Service A" for every pet, the price for Service A changes depending on the pet (for example, Service A will cost more for a heavier dog).

I'm struggling to figure out what my tables should look like. I have "humans" and "pets" tables, which makes sense. When it comes to services however, since the services are occurring at the pet level...what's the primary field for the "services" table? Any other overarching guidance on what these tables could look like?