pg-diff-api

library1.5.3jsnpmunverified

PostgreSQL migration strategy for NodeJS that provides APIs to diff and migrate PostgreSQL schemas and data. Version 1.5.3, released under MIT license. It offers programmatic schema comparison and migration generation, unlike CLI-based alternatives. Features include comparison of database schemas, generation of migration scripts, and support for complex schema objects. Suitable for Node.js >= 8.11.1. Active maintenance with recent releases.

database

npm install pg-diff-api

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · PG-DIFF-API

pg-diff-api

databasejavascriptv1.5.3

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

PgDiffApi

✓ import { PgDiffApi } from 'pg-diff-api'

✗ const PgDiffApi = require('pg-diff-api').PgDiffApi

ESM default export available since v1.5, but named export also works.

compareSchemas

✓ import { compareSchemas } from 'pg-diff-api'

✗ import { compare } from 'pg-diff-api'

Function exported directly; do not confuse with other functions.

generateMigration

✓ import { generateMigration } from 'pg-diff-api'

✗ import { createMigration } from 'pg-diff-api'

Exact function name as per documentation.

Connects to two PostgreSQL databases, compares their schemas, and generates a migration SQL script.

import { PgDiffApi } from 'pg-diff-api'; import { Client } from 'pg'; const sourceClient = new Client({ host: 'localhost', port: 5432, database: 'source_db', user: 'user', password: process.env.DB_PASS ?? '', }); const targetClient = new Client({ host: 'localhost', port: 5432, database: 'target_db', user: 'user', password: process.env.DB_PASS ?? '', }); async function run() { await sourceClient.connect(); await targetClient.connect(); const api = new PgDiffApi({ client: sourceClient }); const diff = await api.compareSchemas(targetClient); console.log('Differences:', JSON.stringify(diff, null, 2)); const migration = await api.generateMigration(diff); console.log('Migration SQL:', migration); await sourceClient.end(); await targetClient.end(); } run().catch(console.error);

Debug

Known issues

breakingIn version 1.5.0, the API changed from callback-based to Promise-based. Old code using callbacks will break.

fix

Update to use async/await or .then() syntax.

affects: <1.5.0

deprecatedDirect use of pg connection strings in PgDiffApi constructor is deprecated. Use pg Client instance instead.

fix

Pass a pg Client object instead of a connection string.

affects: >=1.4.0

gotchaThe compareSchemas method requires both source and target clients; defaulting to same client may produce empty diff.

fix

Ensure you pass a different target client (even if same database, create a new connection).

affects: all

breakingIn version 1.3.0, the output format of compareSchemas changed from an array to an object.

fix

Update code to handle object with properties like 'tables', 'columns', etc.

affects: <1.3.0

Errors

Common errors & fixes

TypeError: PgDiffApi is not a constructor

Importing incorrectly (e.g., default vs named import).

fix

Use 'import { PgDiffApi } from 'pg-diff-api'' instead of 'import PgDiffApi from ...'

Error: Cannot find module 'pg'

Missing or incorrect version of pg dependency.

fix

Run 'npm install pg' and ensure it's the correct version (compatible with pg-diff-api).

TypeError: sourceClient.connect is not a function

Passing a connection string instead of a pg Client instance.

fix

Create a new Client object and connect before passing to PgDiffApi.

Upgrade

Version history

1.5.3latest on npm

Audit

Dependencies

pgrequiredPostgreSQL client for database connections

Agent activity

13 hits · last 30 days

node

Amazon

Resources

githubhttps://github.com/michaelsogos/pg-diff-api ↗

packagepg-diff-api ↗

homepagehttps://github.com/michaelsogos/pg-diff-api#readme ↗