d1-migration

# D1 Migration Workflow Guided workflow for Cloudflare D1 database migrations using Drizzle ORM. ## Standard Migration Flow ### 1. Generate Migration ```bash pnpm db:generate ``` This creates a new `.sql` file in `drizzle/` (or your configured migrations directory). ### 2. Inspect the SQL (CRITICAL) **Always read the generated SQL before applying.** Drizzle sometimes generates destructive migrations for simple schema changes. #### Red Flag: Table Recreation If you see this pattern, the migration will likely fail: ```sql CREATE TABLE `my_table_new` (...); INSERT INTO `my_table_new` SELECT ..., `new_column`, ... FROM `my_table`; -- ^^^ This column doesn't exist in old table! DROP TABLE `my_table`; ALTER TABLE `my_table_new` RENAME TO `my_table`; ``` **Cause**: Changing a column's `default` value in Drizzle schema triggers full table recreation. The INSERT SELECT references the new column from the old table. **Fix**: If you're only adding new columns (no type/constraint changes on existing columns), simplify to: ```sql ALTER TABLE `my_table` ADD COLUMN `new_column` TEXT DEFAULT 'value'; ``` Edit the `.sql` file directly before applying. ### 3. Apply to Local ```bash pnpm db:migrate:local # or: npx wrangler d1 migrations apply DB_NAME --local ``` ### 4. Apply to Remote ```bash pnpm db:migrate:remote # or: npx wrangler d1 migrations apply DB_NAME --remote ``` **Always apply to BOTH local and remote before testing.** Local-onl...