Relational Data Modeling

Phase outcome and project increment

Principles to keep while coding

Guided phase lab

Do these in order. Each step should end with evidence before the next one starts.

1. 01

   List TaskFlow nouns and separate entities from attributes and events.

2. 02

   Model workspace membership as an explicit relation carrying role/state rather than an array on User.

3. 03

   Model boards/lists/tasks and decide which parent IDs should be required.

4. 04

   Model labels through a join table and explain composite uniqueness.

5. 05

   Add comments and timestamps with intentional delete behavior.

6. 06

   Seed a small realistic graph and query it from several directions to validate the model.

pnpm exec prisma migrate dev --name taskflow-core-model
pnpm exec prisma studio

Predict what each command proves before running it. A command is useful only when its output answers a question.

Failures you should know how to diagnose

Lessons

The source chapters come first. Every phase now ends with a guided build, a debugging workshop, and an independent challenge so reading turns into transferable skill.

Exercises that increase independence

Do not leave the phase only because you reached the bottom

Scenario and concept quiz

These questions test engineering choices rather than whether you remember a lesson title.

Reference files

Attempt the work first. Use snapshots to compare a checkpoint, not as a substitute for understanding.

TaskFlow Phase 10 relational model reference

This snapshot is the teaching model used at the end of Phase 10.
It is not a complete final enterprise schema. Later phases add features only when their requirements become concrete.

Important service invariant:
- Task.assigneeId references User. Service logic must verify that the assignee is a member of the task project's workspace.

Prisma remains locked to 7.9.1 for this course.

# Relational modeling checklist

- What durable business fact does this model represent?
- What is its stable identity?
- Which fields are required vs optional?
- Which values must be unique?
- What relationships exist and what is their cardinality?
- Does the relationship carry its own metadata?
- What happens when each parent is deleted?
- Which invariants belong in database constraints?
- Which rules require application/service context?
- What high-value queries will need indexes?
- Is any fact duplicated unnecessarily?
- How will this schema evolve after data exists?

generator client {
  provider     = "prisma-client"
  output       = "../src/generated/prisma"
  moduleFormat = "cjs"
}

datasource db {
  provider = "postgresql"
}

enum MembershipRole {
  OWNER
  ADMIN
  MEMBER
}

enum TaskStatus {
  TODO
  IN_PROGRESS
  DONE