This is an interactive demo. Install the real Chrome Extension →
Private
Open Add user_preferences table + notification settings
sarah-chen wants to merge 8 commits into main from feature/user-preferences
Modified db/schema/users.sql
3 email VARCHAR(255) NOT NULL,
4 email_frequency VARCHAR(20) DEFAULT 'weekly',
4 email VARCHAR(255) NOT NULL,
5 notification_settings JSONB DEFAULT '{}',
6 created_at TIMESTAMP DEFAULT NOW()
SchemaLens button appears on every .sql file
Added db/schema/user_preferences.sql
1CREATE TABLE user_preferences (
2 id SERIAL PRIMARY KEY,
3 user_id INT NOT NULL REFERENCES users(id),
4 theme VARCHAR(20) DEFAULT 'light',
5 language VARCHAR(10) DEFAULT 'en',
6 created_at TIMESTAMP DEFAULT NOW()
7);
Works on Added, Modified, and Removed files
SchemaLens — Schema Diff Result
72

Risk Score: High

2 breaking changes detected. Review before merging.

ChangeTableDetailsRisk
+ Added user_preferences New table with 5 columns Low
~ Modified users Added notification_settings JSONB Medium
− Dropped users Removed email_frequency VARCHAR High ⚠️

Generated by SchemaLens Chrome Extension · View full diff →

Migration Preview

CREATE TABLE user_preferences (
  id SERIAL PRIMARY KEY,
  user_id INT NOT NULL REFERENCES users(id),
  theme VARCHAR(20) DEFAULT 'light',
  language VARCHAR(10) DEFAULT 'en',
  created_at TIMESTAMP DEFAULT NOW()
);

ALTER TABLE users
  ADD COLUMN notification_settings JSONB DEFAULT '{}';

-- Breaking: dropped email_frequency
-- Still referenced by weekly_digest_worker.rb

Stop copy-pasting SQL into browser tabs

The SchemaLens Chrome Extension adds a "Diff in SchemaLens" button to every SQL file on GitHub PR pages. One click sees the full diff, risk score, and migration script.

Install Chrome Extension Try GitHub Action

Free. Works on public repositories. No API key required.

🏢 Need CI/CD integration for your team?

Get the SchemaLens GitHub Action to auto-comment schema diffs on every pull request.

Set Up GitHub Action Book a Demo