Prisma Patterns

Prisma — Project conventions

Applies to Prisma 6.x and 7.x. Preview-only features are flagged inline.

Schema

• One model per domain entity. No technical tables surfaced in the schema (except sessions / tokens).
• Explicit relations via @relation. Always name the relation when there's ambiguity.
• @updatedAt on every model whose content can change.
• String IDs: prefer @default(uuid(7)) (Prisma 5.18+) for new projects — UUIDv7 is time-ordered, which keeps B-tree indexes happy. @default(cuid()) still works but cuid is in maintenance mode per the Prisma team — avoid it in new schemas. Do not use @default(ulid()) — ULID is not a native Prisma generator; use uuid(7) or wire a manual @default via dbgenerated if you truly need ULID.
• Int IDs: @default(autoincrement()).
• Enums for fixed values (roles, statuses, visibility).

Queries

• Always use an explicit select or include. Never findMany() without a filter on a large table.
• omit for sensitive fields (GA in Prisma 6.2+) — exclude fields like password or secret at the query level instead of manual select:

  const user = await prisma.user.findUnique({
    where: { id },
    omit: { password: true },
  });
  

  Prefer this over select-ing every field individually when you only want to hide one or two.
• Avoid N+1: use include with the needed relations rather than loops calling findUnique.
• Cursor-based pagination for long lists (feed, search results). Pattern:

  const items = await prisma.model.findMany({
    take: limit + 1,
    cursor: cursor ? { id: cursor } : undefined,
    skip: cursor ? 1 : 0,
    orderBy: { createdAt: 'desc' },
  });
  const hasMore = items.length > limit;
  if (hasMore) items.pop();
  

• typedSql ⚠️ Preview feature since Prisma 5.19 — still preview as of last verified 2026-04-15. Re-check Prisma's preview-features list before adopting, because preview flags can break, rename, or get removed between minor releases. When you're comfortable pinning a Prisma version and revisiting on upgrades, enable with previewFeatures = ["typedSql"] in the generator block, put .sql files under prisma/sql/, and call them via prisma.$queryRawTyped() — this gives type-safe raw SQL without string interpolation. On a production codebase that can't absorb preview churn, stay on $queryRaw with careful review instead.
• Transactions for multi-model operations that must be atomic.

Migrations

• npx prisma migrate dev --name short-description in dev.
• Never db push in production. Always migrate deploy.
• Review the generated migration before committing — Prisma may emit unexpected DROPs.

Seed

• prisma/seed.js or prisma/seed.ts. Idempotent: prefer upsert over create.
• Realistic seed data — no test123.

Anti-patterns

• ❌ prisma.$queryRaw with unchecked template literals — if the typedSql preview flag is acceptable for your project, prefer $queryRawTyped + .sql files. If you can't depend on preview flags, stay on $queryRaw but sanitize inputs yourself and review each call carefully. Either way, only use raw SQL when the query builder can't express the query.
• ❌ deleteMany() without a where — always spell out the filter
• ❌ Deeply nested writes (> 2 levels) — split into sequential transactions
• ❌ Missing @@index on fields that are frequently filtered