Branded primary keys

Notice the id column:

id: z.number().brand<"public.penguins.id">(),

This uses Zod branding to create a nominal type for your primary key.

What does that give you?

export type Id = Row["id"];

Now Id is not just a number. TypeScript will treat it as a distinct type:

function getPenguin(id: Id) {}
function getZoo(id: ZooId) {}

getPenguin(zooId); // Compilation error.

Why this is useful

The goal is to catch situations like this at compile time:

• Passing the ID variable as an argument to the wrong table.
• Passing user input where a database ID is expected.
• Using raw numbers instead of validated identifiers.

Foreign Keys

If a table contains a foreign key reference, this is also branded on your row object.

flight_attempts.ts

export const row = z.object({
  id: z.number().brand<"public.flight_attempts.id">(),
  penguin: z.number().brand<"public.penguins.id">(),
  // ...
});