Drizzle Team•2y ago

Example failed to run: `pg` does not provide an export named `Pool`

I'm trying to run the example from the README file. I made a minial version, installed pg, @types/pg, drizzle-orm and drizzle-kit and tried to run it via tsx. This is my stripped down example:

import { drizzle } from "drizzle-orm/node-postgres";
import {
  InferModel,
  pgTable,
  serial,
  text,
  timestamp,
} from "drizzle-orm/pg-core";
import { Pool } from "pg";

export const domains = pgTable("domains", {
  id: serial("id").primaryKey(),
  domain: text("domain").notNull(),
  createdAt: timestamp("created_at").defaultNow().notNull(),
  updatedAt: timestamp("updated_at").defaultNow().notNull(),
});

export type Domain = InferModel<typeof domains>;
export type NewDomain = InferModel<typeof domains, "insert">;

const pool = new Pool({
  connectionString: "postgres://robin@localhost/ts-drizzle",
});
const db = drizzle(pool);

async function main() {
  // Insert
  const d: NewDomain = {
    domain: "foo.com",
  };
  const inserted = await db.insert(domains).values(d).returning();
  console.log(inserted);
}

main();

import { drizzle } from "drizzle-orm/node-postgres";
import {
  InferModel,
  pgTable,
  serial,
  text,
  timestamp,
} from "drizzle-orm/pg-core";
import { Pool } from "pg";

export const domains = pgTable("domains", {
  id: serial("id").primaryKey(),
  domain: text("domain").notNull(),
  createdAt: timestamp("created_at").defaultNow().notNull(),
  updatedAt: timestamp("updated_at").defaultNow().notNull(),
});

export type Domain = InferModel<typeof domains>;
export type NewDomain = InferModel<typeof domains, "insert">;

const pool = new Pool({
  connectionString: "postgres://robin@localhost/ts-drizzle",
});
const db = drizzle(pool);

async function main() {
  // Insert
  const d: NewDomain = {
    domain: "foo.com",
  };
  const inserted = await db.insert(domains).values(d).returning();
  console.log(inserted);
}

main();

This is my tsconfig.json:

{
  "compilerOptions": {
    "target": "es2016",
    "module": "commonjs",
    "esModuleInterop": true,
    "strict": true
  }
}

{
  "compilerOptions": {
    "target": "es2016",
    "module": "commonjs",
    "esModuleInterop": true,
    "strict": true
  }
}

Running it:

$ npx tsx main.ts
SyntaxError: The requested module 'pg' does not provide an export named 'Pool'
    at ModuleJob._instantiate (node:internal/modules/esm/module_job:123:21)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async ModuleJob.run (node:internal/modules/esm/module_job:189:5)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:533:24)
    at async loadESM (node:internal/process/esm_loader:91:5)
    at async handleMainPromise (node:internal/modules/run_main:65:12)

$ npx tsx main.ts
SyntaxError: The requested module 'pg' does not provide an export named 'Pool'
    at ModuleJob._instantiate (node:internal/modules/esm/module_job:123:21)
    at processTicksAndRejections (node:internal/process/task_queues:96:5)
    at async ModuleJob.run (node:internal/modules/esm/module_job:189:5)
    at async Promise.all (index 0)
    at async ESMLoader.import (node:internal/modules/esm/loader:533:24)
    at async loadESM (node:internal/process/esm_loader:91:5)
    at async handleMainPromise (node:internal/modules/run_main:65:12)

5 Replies

Dan•2y ago

Weird. Could you try running it with esbuild-register or ts-node? Also, is your project in ESM mode? Also, doesn't seem to be related to Drizzle, cause the error come from pg.

roobOP•2y ago

@bloberenober I removed the "type": "module" now from my package.json and it seems to solve this, thanks! However I do not understand why this error occured because of this Do you have a link or keyword I can google to understand this behaviour?

Dan•2y ago

Well, it's related to ESM support in general. A lot of libraries are only built with CommonJS support and thus are incompatible with ESM. You can just search for ESM vs CommonJS in general, I guess.

roobOP•2y ago

thanks, will do this!

NovemberSpawn•11mo ago

try

import pg from 'pg'

const { Pool } = pg
const pool = new Pool()

import pg from 'pg'

const { Pool } = pg
const pool = new Pool()

Gaming

Programming

Example failed to run: `pg` does not provide an export named `Pool`