Entity Relationships

An overview of how the 10 entities relate to each other.

⚠️ The Most Important Relationship Fact (Read First)

YYNote’s “Lists” are not content ownership containers — they are “tag-filtered views” of content. And there are two independent types of lists:

List Type	What It Is	What It Contains
To-Do List	A tag-filtered “to-do view”	Only to-dos
Sticky Note List	A tag-filtered “sticky note view”	Only sticky notes

What this means in practice:

A sticky note / to-do does not belong to any list (lists are “views,” not “containers”)
A sticky note / to-do can have multiple tags
A list = a set of tag filtering rules (saved search)
The same sticky note / to-do can appear in multiple lists simultaneously (because it may match multiple lists’ tag rules)
Saying “move a sticky note to another list” is inaccurate — the accurate phrasing is “modify the sticky note’s tags so it appears in different lists”
The two list types (to-do lists / sticky note lists) do not interfere with each other: deleting one doesn’t affect the other, and they can’t contain each other’s content

Relationship Overview Diagram

                       ┌──────────┐
                       │  Account  │ ← User identity (must log in to use)
                       └────┬─────┘
                            │
                            ▼
┌────────────────────────────────────────────┐
│            YYNote Data Space               │
│                                            │
│  ┌────────────────┐    ┌────────────────┐   │
│  │   To-Do List   │    │ Sticky Note    │   │
│  │  (To-Do View)  │    │     List       │   │
│  │  Tag-Filtered  │    │ (Note View)    │   │
│  └────────┬───────┘    │  Tag-Filtered  │   │
│           │            └───────┬────────┘   │
│           │  Filter            │  Filter     │
│           ▼                    ▼            │
│       ┌────────┐           ┌────────┐        │
│       │ To-Dos │           │ Sticky │        │
│       │        │           │ Notes  │        │
│       └───┬────┘           └────┬───┘        │
│           │                     │            │
│           │ Attached            │ Attached   │
│           ▼                     ▼            │
│           ┌─────────────────────┐            │
│           │        Tags         │            │
│           └─────────────────────┘            │
│                                            │
│  To-Do side also connects to:              │
│    ├► Recurring To-Do Rules (generate new   │
│    │   to-dos by rule)                      │
│    └► Third-Party Calendar Events           │
│        (read-only display)                  │
│                                            │
└────────────────────────────────────────────┘
                            │
                            │ Sync
                            ▼
                    Other Devices

Correction note: Earlier versions depicted a “List ↔ Sticky Note/To-Do ownership relationship,” which is wrong. The correct relationship is “List ← Tag Rules → Sticky Note/To-Do.”

Relationship Inventory

Tags ↔ Sticky Notes / To-Dos 🟢

Relationship: Many-to-many
Attachment method: Both sticky notes and to-dos can have multiple tags
Deleting a tag: Automatically removes the association from all attached sticky notes/to-dos (sticky note and to-do content is preserved)
UI entry: Tag management + “Add Tag” on the content edit page

To-Do List ← Tags → To-Dos 🟢

Relationship: A to-do list = a set of tag filtering rules; to-dos are “presented” in the list by matching tags
Filtering logic (customer-friendly version):
- List tag rule = “All” → the list shows all to-dos
- List tag rule = “Untagged” → only shows to-dos without tags
- List tag rule = specific tags → only shows to-dos that have any of these tags
The same to-do can appear in multiple to-do lists
“Move to another list” is essentially modifying tags
UI entry: Click different to-do lists in the sidebar — the content area switches display

Sticky Note List ← Tags → Sticky Notes 🟢

Relationship: A sticky note list = a set of tag filtering rules; sticky notes are “presented” in the list by matching tags
Filtering logic: Same as to-do lists
The same sticky note can appear in multiple sticky note lists
“Move to another list” is essentially modifying tags
UI entry: Click different sticky note lists in the sidebar — the content area switches display

To-Do List vs Sticky Note List 🟢

The two list types do not interfere with each other:
- Deleting a to-do list does not affect sticky note lists, and vice versa
- To-do lists will never show sticky notes, and sticky note lists will never show to-dos
The two list types have independent configurations: To-do lists have settings like “Show Lunar Calendar / Hide Schedule,” while sticky note lists have settings like “Hide Sticky Note Time / Hide Sticky Note Tags”

To-Dos ↔ Recurring To-Do Rules 🟢

Relationship: One-to-many (one rule → multiple generated to-dos)
Generation mechanism: Daily scan of all rules → match today → check if already created today → if not, actually create a to-do in the list
Deleting a rule: Previously generated to-dos are not cleaned up (they are independent data records)
UI entry: Recurring to-do management page

To-Dos ↔ Third-Party Calendar Events 🟡

Relationship: One-to-one (each third-party calendar event is displayed as a “read-only to-do”)
Direction: One-way (pulled from external calendar into YYNote)
UI exposure:
- Calendar layer (subscription source): Can create, delete, modify, view
- Event layer: View-only (must edit in the original calendar service)

Account ↔ Membership 🟢

Relationship: Zero-or-one to one (an account can exist without membership)
Binding: Membership is bound to the account, not the device
Activation method: New users get 7-day membership upon registration (consistent across all platforms)
Membership differentiators: Not about quantity caps — it’s that certain features are membership-only (desktop weather, third-party calendar sync, third-party calendar event local notifications, advanced desktop widget layouts, etc.)
Expiry behavior: Returns to “non-member” status, all data retained (features locked, data can be exported via PC client); account does not become invalid
Data ownership: Data always belongs to the user and can be exported at any time

Account ↔ Sync 🟢

Relationship: Enabled upon login
Not logged in: YYNote cannot be used (login dialog pops up immediately when not logged in)
Conflict strategy: Later-saved overwrites earlier-saved + data with uncommitted local modifications is not overwritten

Key “Easily Confused Relationships” Comparison

To-Do List vs Sticky Note List

Dimension	To-Do List	Sticky Note List
Contains	Only to-dos	Only sticky notes
Is	A tag-filtered “to-do view”	A tag-filtered “sticky note view”
Mutual non-interference	Deleting this doesn’t affect sticky note lists	Deleting this doesn’t affect to-do lists
Quantity limit	❌ Unlimited (both members and non-members can create unlimited lists)	❌ Unlimited (both members and non-members can create unlimited lists)

List vs Tag

Dimension	List (To-Do / Sticky Note)	Tag
What it is	A set of tag filtering rules (view)	A content marker
Quantity	Users can create multiple lists	Users can create multiple tags
Relationship	”List ← Tag Rules → Content"	"Content ↔ Tag” (many-to-many attachment)
Deletion	Deleting a list does not affect the content itself	Deleting a tag only removes the attachment
Cross-content	Same content can appear in multiple lists	Same content can have multiple tags
Quantity limit	❌ Unlimited (both members and non-members can create unlimited items)	❌ Unlimited (both members and non-members can create unlimited items)

Recurring To-Do Rules vs To-Dos

Dimension	Recurring To-Do Rule	To-Do
What it is	A periodic generation rule	A specific task item
Lifecycle	Long-lived (until user deletes it)	One-off (can be restored to incomplete after completion)
Mutual deletion impact	Deleting a rule does not affect already-generated to-dos	Deleting a to-do does not affect the rule
Generation relationship	Scans rules daily, if matched, actually creates a to-do	The to-do itself records “which rule it came from”

Delete vs Archive vs Complete

Operation	Applicable To	Recoverable?	UI Entry
Delete	Sticky notes / to-dos / tags / to-do lists / sticky note lists	❌ Irrecoverable	”Delete” button on each detail page
Archive	Sticky notes only	✅ One-click recoverable	”Archive” button on sticky note widget + “Restore” button in archive area
Complete	To-dos only	✅ One-click recoverable	”Complete” checkbox on to-do + “Restore” button in completed area

Special Warning: YYNote has no “recycle bin” / “deleted items” tab. There are related methods in the code but the UI does not invoke them (suspected dead code). User-deleted content cannot be recovered within the product.

The only remedy: Before deletion, users can use the “Export Deleted Records” feature to generate a 小黄条已删除记录YYYYMMDD.xlsx backup file.