Use D1 for managed relational application data with SQLite semantics. For an existing external database, consider Hyperdrive; for per-entity coordination, consider Durable Objects. See storage options before choosing a product.

Read the relevant current documentation before implementing. These references route tasks to the source of truth rather than maintaining copies of APIs, configuration, or plan tables.

Start here

Get started: create a database, bind it to a Worker, and run a first query.
configuration.md: bindings, environments, migrations, local development, and ORM integration.
api.md: parameterized queries, batches, sessions, HTTP access, and testing.
patterns.md: query design, caching, tenant isolation, replication, and recovery.
gotchas.md: errors, types, constraints, performance, and limits.

Check limits and pricing for capacity, allowances, and plan availability; do not infer them from old examples.