Good question, if you were to check out a device to a student that device were to be removed because it is old, do you want to remove that the checkout ever existed?

Now, here’s where “Is a part of” gets a bit tricky in this specific scenario. It’s tempting to think that “Checkout” should be “part of” either “students” or “Devices”. However, a checkout record really depends on both a student and a device.

Here’s why using “Is a part of” for “Checkout” might not be ideal:

• Data Integrity: If “Checkout” is “part of” “Students”, deleting a student would delete their checkout records. This means you lose the history of which devices they checked out. The same issue arises if “Checkout” is “part of” “Devices”.
• Logical Relationship: A checkout isn’t truly “owned” by either the student or the device. It represents a temporary association between the two.

A better approach:

Instead of “Is a part of”, use regular references (Ref) in your “Checkout” table:

• StudentID (Ref): This column references the “Students” table, linking each checkout record to a specific student.
• DeviceID (Ref): This column references the “Devices” table, linking each checkout record to a specific device.

How this works:

• Clear Links: Your “Checkout” table clearly shows which student has checked out which device.
• Data Preservation: Deleting a student or a device won’t automatically delete the checkout records. You retain the checkout history.
• Flexibility: You can easily add more details to the “Checkout” table, like checkout date, due date, and return date.

AppSheet Is a Part Of:

While “Is a part of” is useful for parent-child relationships, your device checkout app requires a more balanced relationship between the three tables. Using references (Ref) provides the flexibility and data integrity you need for this scenario.