Agent-skills-standard nestjs-database

Implement data access patterns, Scaling, Migrations, and ORM selection in NestJS. Use when implementing TypeORM/Prisma repositories, migrations, or database patterns in NestJS. (triggers: **/*.entity.ts, prisma/schema.prisma, TypeOrmModule, PrismaService, MongooseModule, Repository)

install

source · Clone the upstream repo

git clone https://github.com/HoangNguyen0403/agent-skills-standard

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/HoangNguyen0403/agent-skills-standard "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/nestjs/nestjs-database" ~/.claude/skills/hoangnguyen0403-agent-skills-standard-nestjs-database && rm -rf "$T"

manifest: skills/nestjs/nestjs-database/SKILL.md

source content

NestJS Database Standards

Priority: P0 (FOUNDATIONAL)

Selection Strategy

See references/persistence_strategy.md for database selection matrix and scaling patterns (Connection Pooling, Sharding).

Patterns

Repository Pattern: Isolate database logic.
TypeORM: Inject
```
@InjectRepository(Entity)
```
.
Prisma: Create comprehensive
```
PrismaService
```
.
Abstraction: Services should call Repositories, not raw SQL queries.

Configuration (TypeORM)

Async Loading: Always use
```
TypeOrmModule.forRootAsync
```
to load secrets from
```
ConfigService
```
.
Sync: Set
```
synchronize: false
```
in production; use migrations instead.

Migrations

Never use
```
synchronize: true
```
in production.
Generation: Whenever TypeORM entity (
```
.entity.ts
```
) modified, migration MUST generated using
```
pnpm migration:generate
```
.
Audit: Always inspect generated migration file to ensure it matches entity changes before applying.
Production Strategies:
CI/CD Integration (Recommended): Run
```
pnpm migration:run
```
in pre-deploy or post-deploy job (e.g., GitHub Actions, GitLab CI). Ensure production environment variables correctly set.
Manual SQL (For restricted DB access): Use
```
typeorm migration:show
```
to get SQL or simply copy
```
up
```
method's SQL into management tool (like Supabase SQL Editor). Always track manual runs in
```
migrations
```
metadata table.
Zero-Downtime: Use Expand-Contract pattern (Add -> Backfill -> Drop) for destructive changes.
Seeding: Use factories for dev data; only static dicts for prod.

Best Practices

Pagination: Mandatory. Use limit/offset or cursor-based pagination.
Indexing: Define indexes in code (decorators/schema) for frequently filtered columns (
```
where
```
,
```
order by
```
).
Transactions: Use
```
QueryRunner
```
(TypeORM) or
```
$transaction
```
(Prisma) for all multi-step mutations to ensure atomicity.

Anti-Patterns

No synchronize in production: Use explicit migrations;
```
synchronize: true
```
drops and recreates columns.
No raw entity returns from services: Map to DTOs before leaving service layer.
No unpaginated list queries: All list endpoints must implement limit/offset or cursor pagination.