Mutability - Relational - Showcases

Mutable CRUD

Rows are created, read, updated, and deleted. updated_at tracks last modification. Try creating, editing, and deleting rows below.

Label	Code	Active	Created	Updated
Svelte Framework	SVLT-001	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
PostgreSQL Database	PGSQ-002	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
Drizzle ORM	DRZL-003	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
Bun Runtime	BUNR-004	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
Inactive Feature	INAC-005	Inactive	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
Edge Case: Max Int	MAXI-006	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`
Edge Case: Min Values	MINV-007	Active	`Mar 10, 2026, 06:02:21 PM`	`Mar 10, 2026, 06:02:21 PM`

Versioned Records

Every update inserts a snapshot into the history table. Edit a specimen below and watch the history grow.

Current Specimens

Label	Rating	Quantity	Active
Svelte Framework	5	42	Active
PostgreSQL Database	5	100	Active
Drizzle ORM	4	0	Active
Bun Runtime	4	7	Active
Inactive Feature	1	0	Inactive
Edge Case: Max Int	5	2147483647	Active
Edge Case: Min Values	1	0	Active

Version History

Specimen	Version	Change	Label	Rating	Changed By	Changed At
`1`	v1	create	Svelte Framework	5	`seed`	`Mar 10, 2026, 06:02:21 PM`
`2`	v1	create	PostgreSQL Database	5	`seed`	`Mar 10, 2026, 06:02:21 PM`
`3`	v1	create	Drizzle ORM	4	`seed`	`Mar 10, 2026, 06:02:21 PM`
`4`	v1	create	Bun Runtime	4	`seed`	`Mar 10, 2026, 06:02:21 PM`
`5`	v1	create	Inactive Feature	1	`seed`	`Mar 10, 2026, 06:02:21 PM`
`6`	v1	create	Edge Case: Max Int	5	`seed`	`Mar 10, 2026, 06:02:21 PM`
`7`	v1	create	Edge Case: Min Values	1	`seed`	`Mar 10, 2026, 06:02:21 PM`

Soft Delete

deleted_at IS NULL = active. Non-NULL = soft-deleted (recoverable). Click delete to move a document right. Click restore to move it back.

Active Documents 4

Getting Started Guide

API Reference

Deployment Checklist

Draft: Security Audit

Soft-Deleted 1

Old Migration Guide (deleted)

Query Patterns

-- Active only (most common):
WHERE deleted_at IS NULL

-- Soft delete:
UPDATE SET deleted_at = now() WHERE id = $1

-- Restore:
UPDATE SET deleted_at = NULL WHERE id = $1

Append-Only / Immutable

Records are inserted and never modified. There is no Edit button. There is no Delete button. This is intentional.

Audit Log

Seq	Action	Severity	Description	Occurred
`1`	create	info	Created specimen: Svelte Framework	`Mar 10, 2026, 06:02:21 PM`
`2`	create	info	Created specimen: PostgreSQL Database	`Mar 10, 2026, 06:02:21 PM`
`3`	create	info	Created specimen: Drizzle ORM	`Mar 10, 2026, 06:02:21 PM`
`4`	update	info	Updated rating from 4 to 5	`Mar 10, 2026, 06:02:21 PM`
`5`	update	info	Updated price from 100.00 to 150.50	`Mar 10, 2026, 06:02:21 PM`
`6`	delete	warning	Purged expired cache entries	`Mar 10, 2026, 06:02:21 PM`
`7`	login	info	User logged in from 192.168.1.10	`Mar 10, 2026, 06:02:21 PM`
`8`	export	info	Exported 42 records as CSV	`Mar 10, 2026, 06:02:21 PM`
`9`	restore	warning	Restored soft-deleted document	`Mar 10, 2026, 06:02:21 PM`
`10`	update	error	Failed to update: constraint violation	`Mar 10, 2026, 06:02:21 PM`

Add Entry

There is no Edit button. There is no Delete button. This is intentional.

Temporal / Bi-temporal

valid_from / valid_to track when a fact is true in the real world. Use the date picker to query "what was valid on date X?"

All Temporal Records

Description	Valid From	Valid To	Recorded At
Interval arithmetic demo	`Jun 15, 2024, 12:00:00 PM`	Current	`Mar 10, 2026, 06:02:21 PM`
Database migration window	`Mar 1, 2024, 02:00:00 AM`	`Mar 1, 2024, 06:00:00 AM`	`Mar 10, 2026, 06:02:21 PM`
Sprint 1 retrospective	`Jan 29, 2024, 12:00:00 AM`	`Feb 12, 2024, 12:00:00 AM`	`Mar 10, 2026, 06:02:21 PM`
Project kickoff	`Jan 15, 2024, 12:00:00 AM`	Current	`Mar 10, 2026, 06:02:21 PM`
Year-long subscription	`Jan 1, 2024, 12:00:00 AM`	`Jan 1, 2025, 12:00:00 AM`	`Mar 10, 2026, 06:02:21 PM`

Database