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DAL Library

README

@primebrick/dal-pg

Type-driven PostgreSQL Data Access Layer for Primebrick v3.

What it is

A shared library that provides a metadata-based, type-safe Repository for PostgreSQL. Entities are plain TS classes decorated with @Entity, @Column, @Key, @Unique, @AuditableField, @DeletableField. The Repository reads entity metadata at runtime to generate parameterized SQL — no hand-written queries, no DTOs, snake_case everywhere.

The Dal gateway class (getDal()) owns the pg.Pool, registers type parsers, and enforces best-practice pool defaults (statement_timeout, connectionTimeoutMillis, search_path, application_name) to prevent connection throttling under high-async REST traffic. One singleton instance per process per database, reused across all requests — zero per-request allocation.

Consumers

• primebrick-us-v3 (microservices) — Phase 2 (after DAL is released)
• primebrick-be-v3 (backend) — Phase 3 (after US integration)

Commands

Action	Command
Install	pnpm install
Build	pnpm run build
Test	pnpm test
Test (watch)	pnpm test:watch
Benchmarks	pnpm test:benchmark

Architecture

Code
src/
  dal/            Dal gateway — pool ownership, type parsers, getDal singleton, withClient
  meta/           entity metadata + decorators + column PG<->JS coercion
  query/          query DSL (filters, sorts, joins, projection) + streaming
  repository/     the Repository class — type-driven CRUD, finders, bulk ops
  errors/         NotFoundError, MultipleRowsError
  types/          FindOptions, BulkOptions, AuditPort, LoggerPort
  audit/          auditable field types + join helpers
  index.ts        public barrel

Key design decisions

• snake_case everywhere — DB columns, TS properties, JSON responses all use snake_case. No DTO transformation.
• RETURNING * on all writes — the DB returns the full row after insert/update/delete, hydrated directly into the entity shape.
• throwIfNotFound: true by default on all finders — pass { throwIfNotFound: false } to get null instead.
• deletedRecords: "EXCLUDED" by default — soft-deleted rows are excluded from finders unless { deletedRecords: "ONLY" } or "INCLUDED".
• TEMP TABLE strategy for updateMany / upsertMany — CREATE TEMP TABLE ... ON COMMIT DROP → batched INSERT → single UPDATE FROM / INSERT SELECT ON CONFLICT. Atomic, SQL-injection safe, scales to millions of rows.
• Audit-aware ON CONFLICT — upsertMany preserves created_at/created_by on conflict, stamps updated_at/updated_by/version.
• bigint via INT8_OID type parser — int8 columns return native bigint, not strings. Registered by the Dal gateway (consumers no longer need to do this manually).
• Metadata-driven numeric handling — @Column({ dbType: "numeric", precision: 15, scale: 2 }) returns number when safe, string when precision overflows Number.MAX_SAFE_INTEGER.
• Dal gateway — getDal(config) singleton owns the pool, registers type parsers, sets statement_timeout/search_path/application_name on every connection. withClient(fn, { timeoutMs }) for transactions and per-call timeout override. close() for graceful shutdown.
• statement_timeout as anti-throttling — default 30s per session. A slow query holding a connection starves the pool under burst traffic; the timeout guarantees connection release. Per-call override for bulk ops (SET LOCAL inside tx) and ad-hoc long queries (withClient).

GitFlow

This repository follows GitFlow. See docs/gitflow.md for complete rules.

AI documentation

• AGENTS.md — entry point for AI agents
• docs/ai/ — AI-first documentation
• .devin/rules/ — always-on rules for Devin agents
• .devin/skills/ — invokable skills

License

MIT — see LICENSE