database-schema

# Database Schema Awareness Skill **Problem:** Claude forgets schema details mid-session - wrong column names, missing fields, incorrect types. TDD catches this at runtime, but we can prevent it earlier. --- ## Core Rule: Read Schema Before Writing Database Code **MANDATORY: Before writing ANY code that touches the database:** ``` ┌─────────────────────────────────────────────────────────────┐ │ 1. READ the schema file (see locations below) │ │ 2. VERIFY columns/types you're about to use exist │ │ 3. REFERENCE schema in your response when writing queries │ │ 4. TYPE-CHECK using generated types (Drizzle/Prisma/etc) │ └─────────────────────────────────────────────────────────────┘ ``` **If schema file doesn't exist → CREATE IT before proceeding.** --- ## Schema File Locations (By Stack) | Stack | Schema Location | Type Generation | |-------|-----------------|-----------------| | **Drizzle** | `src/db/schema.ts` or `drizzle/schema.ts` | Built-in TypeScript | | **Prisma** | `prisma/schema.prisma` | `npx prisma generate` | | **Supabase** | `supabase/migrations/*.sql` + types | `supabase gen types typescript` | | **SQLAlchemy** | `app/models/*.py` or `src/models.py` | Pydantic models | | **TypeORM** | `src/entities/*.ts` | Decorators = types | | **Raw SQL** | `schema.sql` or `migrations/` | Manual types required | ### Schema Reference File (Recommended) Create `_project_specs/schema-reference.md` for quick lookup: ```markdown # Database Sch...