Manage a D1 database schema with wrangler migrations, testing against a local dev database before applying the same migrations to the remote/production database.

Documented steps

1. Create a database and get its binding config: npx wrangler d1 create <NAME>, then add the printed block to wrangler.jsonc: {"d1_databases":[{"binding":"DB","database_name":"<NAME>","database_id":"<UUID>"}]}. Doc: https://developers.cloudflare.com/d1/get-started/
2. Generate an empty migration file: npx wrangler d1 migrations create <DATABASE> "<message>" — writes a numbered file like 0000_create_user_table.sql into migrations/ (customizable via migrations_dir/migrations_table/migrations_pattern in the binding). Doc: https://developers.cloudflare.com/d1/reference/migrations/
3. Edit the generated .sql file with your DDL/DML statements.
4. List pending migrations against your local dev DB: npx wrangler d1 migrations list <DATABASE> --local (use --remote to check the deployed DB instead).
5. Apply locally first for testing: npx wrangler d1 migrations apply <DATABASE> --local — runs unapplied files and records them in the d1_migrations tracking table.
6. Apply the same migrations to production: npx wrangler d1 migrations apply <DATABASE> --remote — prompts for confirmation (skipped in CI) and captures a backup first; a failing migration is rolled back while prior successful ones stay applied.
7. Query the database from a Worker using the binding: const { results } = await env.DB.prepare("SELECT * FROM Customers WHERE CompanyName = ?").bind("Bs Beverages").run();. Doc: https://developers.cloudflare.com/d1/get-started/
8. Iterate with npx wrangler dev (talks to the --local DB by default) before shipping with npx wrangler deploy.