Compare the rule with concrete cases
Fictional assignment selects a project and a checklist. Each must exist, and the checklist must belong to that project. P1 and C2 both exist, but C2 belongs to P2. Their individual validity does not make P1/C2 a valid pair.
| Selected project | Selected checklist | Checklist owner project | Pair valid |
|---|---|---|---|
| P1 | C1 | P1 | Yes |
| P1 | C2 | P2 | No |
| P2 | C2 | P2 | Yes |
Work through the distinction
The condition compares the relationship reference, not similar titles. A checklist called “General” does not become usable for every project merely because its display name is generic.
P1 is changed to P2 while C1 remains selected. What must be rechecked?
Show the worked answer
Recheck the pair. C1 belongs to P1, so the updated P2/C1 combination is invalid.
Acceptance wording to adapt
Before saving an assignment, verify both references exist and checklist.project_id equals selected_project_id. Re-evaluate this condition when either selection changes; reject a mismatched pair.