Revise "Working with databases"

[samdark]

Q	A
Is bugfix?	❌
New feature?	❌
Breaks BC?	❌
Tests pass?	✔️
Fixed issues	-

[Copilot]

Pull request overview

Updates the “Working with databases” guide to treat slug as a persisted field on the Page entity instead of deriving it via getSlug(), and adjusts the accompanying repository/view/action examples accordingly.

Changes:

• Add a slug property to the Page entity and generate it during Page::create() when not provided.
• Update repository persistence and hydration to use $page->slug / $row['slug'].
• Update view/action snippets to use the persisted slug instead of getSlug().

[Copilot]

Page::create() declares $slug as string but gives it a null default value. This is invalid in PHP and will fail static analysis / runtime type checks. Make the parameter nullable (?string $slug = null) or use a non-null default (and adjust the null-coalescing logic accordingly).

Suggested change

	string $slug = null,
	?string $slug = null,

[Copilot]

The EditAction snippet imports Yiisoft\Strings\Inflector but doesn’t use it. This makes the example inconsistent and may confuse readers; please remove the unused import or use it explicitly in the action.

Suggested change

use Yiisoft\Strings\Inflector;