---

name: db-explorer description: Connect to PostgreSQL, MySQL, or SQLite databases to explore schema structure, table relationships, and generate ERD diagrams. Use when the user asks to explore a database, document schema, or understand table relationships.

Database Explorer

Analyze database schema and generate Markdown documentation with Mermaid ERD diagrams.

Workflow

1. Check credentials: Run scripts/db_connect.py --check-env
2. If credentials missing: Ask the user for:
   • Database type (postgres/mysql/sqlite)
   • For SQLite: path to the .db file
   • For PostgreSQL/MySQL: host, port, database name, username, password
3. Test connection: scripts/db_connect.py --test --type <type> --host <host> --database <db> --user <user> --password <pass>
4. Extract schema: scripts/schema_extractor.py --output markdown --file .tmp/docs/db-schema-{dbname}.md

Environment Variables (optional)

Users can pre-set credentials to skip prompts:

• PostgreSQL: PGHOST, PGPORT, PGDATABASE, PGUSER, PGPASSWORD
• MySQL: MYSQL_HOST, MYSQL_TCP_PORT, MYSQL_DATABASE, MYSQL_USER, MYSQL_PWD
• SQLite: SQLITE_DATABASE
• Alternative: DATABASE_URL (e.g., postgresql://user:pass@host:5432/dbname)

Mermaid ERD Notation

• ||--|| One-to-one
• ||--o{ One-to-many
• ||--|{ One-to-many (required)

Security

• Never log or echo passwords in output
• Query system tables only, never user data