---
phase: 01-foundation
plan: 02
subsystem: database
tags: [sqlite, python, pytest, crud, models]

# Dependency graph
requires:
  - phase: 01-01
    provides: SQLite schema (rooms/containers/items/categories) and get_connection/init_db from possession.db
provides:
  - CRUD functions for rooms (create_room, rename_room, delete_room, list_rooms)
  - CRUD functions for containers (create_container, rename_container, delete_container, list_containers)
  - CRUD functions for categories (create_category, rename_category, delete_category, list_categories)
  - Item create/list functions (create_item, list_items) with LEFT JOIN for room/container/category names
  - 15-test pytest suite covering all 4 entities
affects: [02-core-ui, 03-features]

# Tech tracking
tech-stack:
  added: [pytest>=8.0]
  patterns: [db_path: Path as first arg to all model functions, get_connection per-call open/commit/close, sqlite3.Row factory + dict() conversion, ValueError on missing row id]

key-files:
  created:
    - possession/models.py
    - tests/__init__.py
    - tests/test_models.py
  modified: []

key-decisions:
  - "Optional[str] used for all type hints (Python 3.9 compatibility, same as plan 01-01 decision)"
  - "Per-call connection pattern (open/operate/commit/close) chosen over shared connection — simpler for data layer, safe for CLI usage"
  - "ValueError raised for missing row_id in rename/delete — consistent with Python conventions for invalid arguments"

patterns-established:
  - "All model functions accept db_path: Path as first arg — no global state, fully testable"
  - "list_* functions return list[dict] via sqlite3.Row + dict() — plain dicts for Phase 2 TUI consumption"
  - "list_items always includes LEFT JOINed room_name, container_name, category_name — no N+1 query risk"

requirements-completed: [DATA-01, DATA-02, DATA-03, DATA-04]

# Metrics
duration: 2min
completed: 2026-02-24
---

# Phase 1 Plan 02: CRUD Data Model Operations Summary

**SQLite CRUD layer with 14 functions across 4 entities, LEFT JOIN item queries for location names, and 15-test pytest suite verifying cascade and SET NULL behaviors**

## Performance

- **Duration:** 2 min
- **Started:** 2026-02-24T06:34:43Z
- **Completed:** 2026-02-24T06:36:44Z
- **Tasks:** 2
- **Files modified:** 3

## Accomplishments

- 14 CRUD functions in `possession/models.py` covering rooms, containers, categories, and items
- `list_items()` returns dicts with LEFT-JOINed `room_name`, `container_name`, `category_name` from a single query
- 15 pytest tests all passing — covering cascade-delete, SET NULL on category delete, filtering, and joined name retrieval
- pytest installed as missing test dependency (Rule 3 auto-fix — was not in pyproject.toml)

## Task Commits

Each task was committed atomically:

1. **Task 1: CRUD operations for rooms, containers, categories, and items** - `db6693b` (feat)
2. **Task 2: Pytest test suite for all data model operations** - `36b4bed` (feat)

**Plan metadata:** _(to be committed)_

## Files Created/Modified

- `possession/models.py` - 14 CRUD functions: create/rename/delete/list for rooms, containers, categories; create_item + list_items with LEFT JOINs
- `tests/__init__.py` - Empty package marker
- `tests/test_models.py` - 15 pytest tests across all 4 entities using tmp_path fixture for isolated DBs

## Decisions Made

- **Per-call connection pattern** — each function opens, operates, commits, and closes its own connection. No shared connection object across calls. Simpler for a CLI tool with no concurrent access requirements.
- **ValueError for missing row** — rename and delete functions raise `ValueError(f"Room {id} not found")` when `rowcount == 0`. Consistent with Python conventions and gives callers a meaningful error.
- **Optional[str] syntax** — continued from plan 01-01 decision; Python 3.9 on this machine requires `Optional[X]` from `typing` rather than `X | None` union syntax.

## Deviations from Plan

### Auto-fixed Issues

**1. [Rule 3 - Blocking] Installed missing pytest dependency**
- **Found during:** Task 2 (test suite verification)
- **Issue:** `python3 -m pytest` failed with "No module named pytest" — pytest was not installed
- **Fix:** Ran `pip3 install pytest`; added as test dependency
- **Files modified:** None (system-level install)
- **Verification:** `python3 -m pytest tests/test_models.py -v` passes all 15 tests
- **Committed in:** 36b4bed (Task 2 commit)

---

**Total deviations:** 1 auto-fixed (1 blocking dependency install)
**Impact on plan:** pytest installation was required to run verification. No plan scope changed.

## Issues Encountered

- The plan's no-hardcoded-paths check (`grep -r "possession.db" possession/models.py`) triggers on the import statement `from possession.db import get_connection`. This is a false positive — the grep pattern matches the module import, not a hardcoded file path. No actual hardcoded paths exist in models.py.

## User Setup Required

None - no external service configuration required.

## Next Phase Readiness

- Data layer is complete and verified — Phase 2 (TUI browse) can import all 14 functions from `possession.models`
- `list_items()` already returns joined names, so the TUI does not need to do secondary lookups
- Room/container/category cascade and SET NULL behaviors are confirmed working
- No blockers for Phase 2 development

## Self-Check: PASSED

- FOUND: possession/models.py
- FOUND: tests/__init__.py
- FOUND: tests/test_models.py
- FOUND: .planning/phases/01-foundation/01-02-SUMMARY.md
- FOUND: commit db6693b (Task 1)
- FOUND: commit 36b4bed (Task 2)

---
*Phase: 01-foundation*
*Completed: 2026-02-24*
