Schema, Generator & First Model Prisma Schema Language without hiding the relational model
Course rule: Prisma CLI, @prisma/client and @prisma/adapter-pg are locked to 7.9.1. Newer Prisma releases are not substituted halfway through the course.
1. The Prisma Schema Has Three Responsibilities At this point schema.prisma describes: the client generator, the database provider and the first minimal application model. Credentials stay outside this file. apps/api/prisma/schema.prisma
generator client { provider = "prisma-client" output = "../src/generated/prisma" moduleFormat = "cjs" }
datasource db { provider = "postgresql" }
model Todo { id String @id @default(cuid()) title String completed Boolean @default(false) createdAt DateTime @default(now()) updatedAt DateTime @updatedAt }
2. Generator Block provider = "prisma-client" selects Prisma 7's generated TypeScript client. output is required in Prisma 7 and places generated code under src/generated/prisma so Nest's TypeScript build can see it.
NESTJS MODULE FORMAT This course keeps the existing NestJS CommonJS build. moduleFormat = "cjs" aligns the generated Prisma Client with that build instead of converting the entire backend to ESM midway through the course.
3. Datasource Block The datasource says only that PostgreSQL is the database provider. The connection URL is handled by prisma.config.ts in Prisma 7.
4. First Minimal Todo Model This model exists only to teach the migration and client-generation workflow. Phase 10 will revisit the relational design before the production CRUD phase.
id Application identifier generated as a cuid Primary key
title Required task title NOT NULL text
completed Defaults false Boolean + default
createdAt Creation timestamp Default now()
updatedAt Updated by Prisma on writes Application-managed timestamp
5. Validate Before Migrating From: taskflow\apps\api
pnpm exec prisma validateValidation checks Prisma configuration/schema correctness. It is not a substitute for reviewing migration SQL and it does not prove that every runtime query works.
Checkpoint Do not continue until prisma validate succeeds and you can explain why moduleFormat, output and datasource provider are separate decisions.
Prisma improves developer ergonomics, but migrations and generated queries still change a real relational database. You should be able to inspect both sides.
Restate the goal of “Schema Generator and First Model” as one observable behavior. Write the success signal before touching code.
Trace the boundary map: domain intent → Prisma Client → generated SQL → PostgreSQL → mapped result. Mark the one boundary this lesson changes.
Inspect the current repository state and record the exact files, route, table, or runtime involved. Avoid creating an abstraction before you can name the existing owner.
Implement the smallest vertical slice. Add one coherent change, run the narrowest verification command, and read the output before continuing.
Connect the slice to TaskFlow’s phase artifact: Prisma schema + migration history + generated client + NestJS PrismaService connected to TaskFlow PostgreSQL.. Verify behavior from the outside as a user or API client would.
Create one controlled failure that is safe to reproduce. Predict the symptom first, capture evidence, locate the earliest broken boundary, then fix only that cause.
Close the reference and rebuild or explain the core change from memory. Record what you would monitor or test before trusting the same change in production.
const tasks = await prisma.task.findMany({
where: { workspaceId },
orderBy: [{ createdAt: "desc" }, { id: "desc" }],
take: 20,
});Do not copy this as a finished answer. Predict what each boundary does, type the smallest useful slice, run it, then compare the result with your prediction.
Verify connection string, host, port, SSL/pooler mode, network reachability, and which environment file the process loaded.
Read the generated SQL before applying it and compare the change against existing production-shaped data.
Without copying the final source, create a second small scenario that applies “Schema Generator and First Model” to a different TaskFlow resource or input. Write the acceptance criteria first, implement it, and provide the evidence that each criterion is satisfied.
Generate the client and wire a PrismaService into NestJS with controlled lifecycle.
Use the smallest change that demonstrates this lesson. Stop after it works and capture evidence.Creating a new PrismaClient per request
Predict the symptom before causing the failure. Then locate the earliest boundary where reality diverges from expectation.Why does this responsibility live here, what input does it trust, what output proves success, and what would go wrong if another layer owned it?
If your explanation is vague, repeat the boundary trace before moving on.Close the reference. Reproduce the core idea from memory or explain the exact request/data flow aloud. Then check your diff or notes for accidental shortcuts that bypass validation, authorization, error handling, or verification earned in earlier phases.