generate-db-design - SKILL.md Agent Skill

name: generate-db-design description: "Generate or update database design document with Mermaid ERD. Init mode renders database-design.md from ProjectModel; update mode applies a Delta to existing docs; sync is a 2-step propose→apply that scans ORM models in the codebase." category: documentation keywords: [database, erd, mermaid, schema, migration] argument-hint: "init|update|sync|apply-sync [options]" metadata: author: docs-hero version: "1.0.0"

Generate DB Design Skill

Sub-skill that owns morkit/output/docs/database-design.md. Single-language output (JP / EN / VN). Embeds a Mermaid erDiagram for tables + relationships.

Environment (plugin context)

CLAUDE_PLUGIN_ROOT="${CLAUDE_PLUGIN_ROOT:?must be set by Claude Code}"
VENV="${HOME}/.claude/plugins/data/docs-hero/.venv"
PY="${VENV}/bin/python3"
DB_SCRIPTS="${CLAUDE_PLUGIN_ROOT}/skills/generate-db-design/scripts"
ORCH_SCRIPTS="${CLAUDE_PLUGIN_ROOT}/skills/docs-hero-orchestrator/scripts"
PROJECT_DOCS_DIR="${PWD}/docs"
PROJECT_META="${PWD}/.docs-hero-meta.json"

Modes

Mode	Purpose
`init`	Render `morkit/output/docs/database-design.md` from a ProjectModel JSON
`update`	Apply Delta filtered for DB scope (TABLE/INDEX/REL/ENUM)
`sync`	Scan ORM models in codebase, write proposal — DOES NOT touch docs
`apply-sync`	Read proposal (with user-checked boxes) → convert to Delta

Init Workflow

"$PY" "$DB_SCRIPTS/render_db_design.py" \
  --project-model "$PROJECT_MODEL" \
  --language JP \
  --output "$PROJECT_DOCS_DIR/database-design.md"

Section IDs (stable for diff engine):

TBL-{id}        # Per-table H3 anchor (e.g. TBL-001, TBL-USERS)
IDX-{id}        # Per-index
REL-{id}        # Per-relationship
ENUM-{id}       # Per-enum
ERD             # Single Mermaid block

Update Workflow

The orchestrator pre-filters Delta to DB scope, then runs the standard diff-engine flow (detect_manual_edits → compute_diff → apply_patch).

Sync Workflow (2-step)

Step 1: propose

"$PY" "$DB_SCRIPTS/db_sync_propose.py" \
  --codebase-paths "$CODEBASE_PATHS" \
  --existing-doc "$PROJECT_DOCS_DIR/database-design.md" \
  --output "${PWD}/.tmp/db-sync-proposal.md"

Scans Prisma / TypeORM / Sequelize / Django / SQLAlchemy / GORM / raw SQL models, diffs with documented tables, writes a markdown proposal with [ ] checkboxes. No doc changes.

Step 2: apply-sync

"$PY" "$DB_SCRIPTS/db_sync_apply.py" \
  --proposal "${PWD}/.tmp/db-sync-proposal.md" \
  --output "${PWD}/.tmp/db-delta.json"

Parses checked items, emits Delta JSON for the standard update flow.

File Ownership

This skill owns:

morkit/output/docs/database-design.md

It does not modify:

morkit/output/docs/srs.md
morkit/output/docs/api-docs.md

References

templates/database-design-template.md — full structure reference
references/mermaid-erd-syntax.md — Mermaid ERD cheat sheet