// @ozaco/db

Postgres

A Postgres driver for the `DB` protocol, backed by a connection pool.

import from@ozaco/db/impl/postgres

@ozaco/db/impl/postgres provides PostgresDB, a concrete implementation of the DB protocol backed by a pooled Postgres client. Install it with a PostgresConfig — a connection URL, your SchemaDef, and an optional pool size — and the effect scope gains a QueryBuilder reachable through useDatabase().

On install the driver builds the Drizzle table objects from your schema, opens a connection pool (default max of 10), and runs applyMigrations against the postgres dialect. Because Postgres rejects a REFERENCES to a table that does not yet exist, migrations order table creation by foreign-key dependency. The pool is drained through the protocol’s close action.

Postgres-specific types are used during DDL generation — SERIAL for auto-increment primary keys, TIMESTAMP WITH TIME ZONE, BYTEA for blobs, VARCHAR(n) — and raw errors are classified into DbErrorCode tags (for example a unique-constraint violation becomes unique-violation).

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Plugin Configuration

Plugin

const

PostgresDB

The installable Postgres implementation of the `DB` protocol.

signature

const PostgresDB: Plugin<QueryBuilder, [PostgresConfig], DBActions>

// DBActions:
PostgresDB.actions.close(): Future<void>

Built from DB.implement({ name: 'postgres', version: '0.0.1', setup }). Its context is the QueryBuilder; its setup argument is a PostgresConfig. Pass it to install from @ozaco/std/plugin, then query through the returned builder or useDatabase().

Migrations run automatically during setup, and close ends the pool. transaction on the query builder maps to a real Postgres transaction, rolling back if the callback fails.

example

import { defineSchema } from '@ozaco/db'
import { PostgresDB } from '@ozaco/db/impl/postgres'
import { install } from '@ozaco/std/plugin'

function* main() {
  const db = yield* install(PostgresDB, {
    url: 'postgres://user:pass@localhost:5432/app',
    schema: defineSchema({ users }),
    max: 20,
  })

  return yield* db.from(users).where({ active: true }).all()
}

Configuration

iface

PostgresConfig

Install options: a connection URL, the schema, and an optional pool size.

signature

interface PostgresConfig {
  readonly url: string
  readonly schema: SchemaDef
  readonly max?: number
}

url is a standard postgres:// connection string. schema is a SchemaDef from defineSchema, migrated on install. max caps the number of pooled connections and defaults to 10.

example

import { defineSchema } from '@ozaco/db'
import type { PostgresConfig } from '@ozaco/db/impl/postgres'

const config: PostgresConfig = {
  url: 'postgres://user:pass@localhost:5432/app',
  schema: defineSchema({ users }),
  max: 20,
}