Agent-skills-standard database-postgresql

Enforce repository patterns, zero-downtime migrations, and indexing standards for PostgreSQL with TypeORM or Prisma. Use when defining entities, writing migrations, adding RLS policies, or optimizing query performance. (triggers: **/*.entity.ts, prisma/schema.prisma, **/migrations/*.sql, TypeOrmModule, PrismaService, PostgresModule)

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 "$T/skills/database/database-postgresql" ~/.claude/skills/hoangnguyen0403-agent-skills-standard-database-postgresql && rm -rf "$T"

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

source content

PostgreSQL Database Standards

Priority: P0 (FOUNDATIONAL)

Patterns & Architecture

Repository Pattern: Isolate database logic. Use
```
@InjectRepository()
```
or
```
PrismaService
```
.
Relationship Integrity: Avoid redundant raw ID columns. Favor relation properties.

Migrations (Strict Rules)

NEVER use
```
synchronize: true
```
in production.
Generation: Modify
```
.entity.ts
```
-> run
```
pnpm migration:generate
```
.
Zero-Downtime: Use Expand-Contract pattern (Add -> Backfill -> Drop) for destructive changes.
RLS:
```
typeorm migration:generate
```
cannot detect Row-Level Security. Use raw
```
queryRunner.query()
```
SQL for RLS.

See implementation examples for Expand-Contract migration patterns.

Performance & Gotchas

Pagination: Mandatory. Use limit/offset or cursor-based pagination.
Indexing: Define indexes in code for frequently filtered columns. RLS columns MUST indexed.
Transactions: Use
```
QueryRunner
```
or
```
$transaction
```
for multi-step mutations.

Anti-Patterns

No N+1 queries: Use query builders or eager-load relations instead of lazy-loading in loops.
No heavy RLS joins: Keep RLS predicates simple; move complex logic to query/view layer.
No synchronize in production: Always run explicit migrations;
```
synchronize: true
```
destructive.

References

SQL Gotchas (UPDATE FROM)