README

# Create database
wrangler d1 create <database-name>

# Execute migration
wrangler d1 migrations apply <db-name> --remote

# Local development
wrangler dev

// .all() - Returns all rows; .first() - First row or null; .first(col) - Single column value
// .run() - INSERT/UPDATE/DELETE; .raw() - Array of arrays (efficient)
const { results, success, meta } = await env.DB.prepare('SELECT * FROM users WHERE active = ?').bind(true).all();
const user = await env.DB.prepare('SELECT * FROM users WHERE id = ?').bind(userId).first();

// Multiple queries in single round trip (atomic transaction)
const results = await env.DB.batch([
  env.DB.prepare('SELECT * FROM users WHERE id = ?').bind(1),
  env.DB.prepare('SELECT * FROM posts WHERE author_id = ?').bind(1),
  env.DB.prepare('UPDATE users SET last_access = ? WHERE id = ?').bind(Date.now(), 1)
]);

// Create long-running session for analytics/migrations (up to 15 minutes)
const session = env.DB.withSession();
try {
  await session.prepare('CREATE INDEX idx_heavy ON large_table(column)').run();
  await session.prepare('ANALYZE').run();
} finally {
  session.close(); // Always close to release resources
}

// Read from nearest replica for lower latency (automatic failover)
const user = await env.DB_REPLICA.prepare('SELECT * FROM users WHERE id = ?').bind(userId).first();

// Writes always go to primary
await env.DB.prepare('UPDATE users SET last_login = ? WHERE id = ?').bind(Date.now(), userId).run();

# Database management
wrangler d1 create <db-name>
wrangler d1 list
wrangler d1 delete <db-name>

# Migrations
wrangler d1 migrations create <db-name> <migration-name>    # Create new migration file
wrangler d1 migrations apply <db-name> --remote             # Apply pending migrations
wrangler d1 migrations apply <db-name> --local              # Apply locally
wrangler d1 migrations list <db-name> --remote              # Show applied migrations

# Direct SQL execution
wrangler d1 execute <db-name> --remote --command="SELECT * FROM users"
wrangler d1 execute <db-name> --local --file=./schema.sql

# Backups & Import/Export
wrangler d1 export <db-name> --remote --output=./backup.sql  # Full export with schema
wrangler d1 export <db-name> --remote --no-schema --output=./data.sql  # Data only
wrangler d1 time-travel restore <db-name> --timestamp="2024-01-15T14:30:00Z"  # Point-in-time recovery

# Development
wrangler dev --persist-to=./.wrangler/state