Slugs from titles — Examples

Slugs from titles

Generate a URL-safe slug from a title in the database, so it’s always in sync and never set by hand. A slugify function does the transform; a rewrite applies it on insert and update.

use extension 'unaccent';

@language plpgsql
function slugify(value: text) -> text {
  return regexp_replace(lower(public.unaccent(value)), '[^a-z0-9]+', '-', 'gi');
};

type Article extends Base {
  required title: str;
  slug: str {
    constraint exclusive;
    rewrite create, update := slugify(__new__.title);
  };
}

• rewrite create, update := slugify(__new__.title) folds into a BEFORE INSERT and BEFORE UPDATE trigger. __new__ is the row being written, so the slug is recomputed whenever the title changes.
• constraint exclusive makes the slug unique.
• unaccent folds accented characters (Crème → creme).

Inserting only needs the title — the slug is filled in by the trigger:

insert Article { title := $title<str> };

From generated code

Saved as create_article.aql, the query becomes a typed function. The slug comes back on the returned row — you never compute it in application code:

TypeScript

const article = await runner.query.createArticle({ title: "Crème Brûlée" });
// article.slug === "creme-brulee"

Go

article, err := runner.Query.CreateArticle(ctx, gen.CreateArticleParams{Title: "Crème Brûlée"})
// *article.Slug == "creme-brulee"