Configuration

Connection pools

BigAl requires a PostgreSQL connection pool that implements PoolLike. Three drivers are supported:

postgres-pool (recommended)

import { Pool } from 'postgres-pool';
import { initialize } from 'bigal';

const pool = new Pool({
  connectionString: 'postgres://user:pass@localhost/mydb',
});

const repos = initialize({ models, pool });

node-postgres (pg)

import pg from 'pg';

const pool = new pg.Pool({
  connectionString: 'postgres://user:pass@localhost/mydb',
});

const repos = initialize({ models, pool });

Neon serverless

import { Pool } from '@neondatabase/serverless';

const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
});

const repos = initialize({ models, pool });

Read replicas

Separate read and write pools by passing readonlyPool:

const pool = new Pool('postgres://localhost/mydb');
const readonlyPool = new Pool('postgres://readonly-host/mydb');

const repos = initialize({
  models,
  pool,
  readonlyPool,
});

find(), findOne(), and count() use readonlyPool. create(), update(), and destroy() use pool.

Individual queries can override the pool:

const product = await productRepository
  .findOne({
    pool: writePool,
  })
  .where({ id: 42 });

Multiple databases

Use named connections for models that live in different databases:

@table({ name: 'audit_logs', connection: 'audit' })
export class AuditLog extends Entity {
  // ...
}

const repos = initialize({
  models: [Product, AuditLog],
  pool: mainPool,
  connections: {
    audit: {
      pool: auditPool,
      readonlyPool: auditReadonlyPool,
    },
  },
});

Models without a connection option use the top-level pool.

Expose callback

The expose callback is invoked for each repository after creation:

const repos = initialize({
  models,
  pool,
  expose(repository, tableMetadata) {
    console.log(`Initialized ${tableMetadata.name}`);
  },
});

Debugging

Set the DEBUG_BIGAL environment variable to log generated SQL:

DEBUG_BIGAL=true node app.js