Type Utilities

Relayer exports utility types for building type-safe custom methods and API handlers. Three ways to use them, from simplest to most powerful.

From entity class (simplest)

Works directly with your entity class. No client instance needed.

import type { DotPaths, OrderByType, SelectType, WhereType } from '@relayerjs/drizzle';

type UserSelect = SelectType<User>;
type UserWhere = WhereType<User>;
type UserPaths = DotPaths<User>; // "id" | "firstName" | "fullName" | "postsCount" | ...
type UserOrderBy = OrderByType<User>;

Includes all scalar columns, computed fields, derived fields, AND/OR/NOT. Does not include relation resolution (use InferModel for that).

function findActiveUsers(where: WhereType<User>) {
  return r.users.findMany({ where: { ...where, active: true } });
}

From client with InferModel (full power)

For relation dot paths and cross-entity computed/derived fields, extract a resolved model from the client:

import type { DotPaths, InferModel, OrderByType, SelectType, WhereType } from '@relayerjs/drizzle';

type Post = InferModel<typeof r, 'posts'>;

type PostWhere = WhereType<Post>; // includes author.fullName, author.postsCount
type PostPaths = DotPaths<Post>; // "id" | "title" | "author.fullName" | "author.orderSummary.totalAmount" | ...
type PostSelect = SelectType<Post>; // { author?: boolean | { fullName?: boolean; postsCount?: boolean; ... }; ... }
type PostOrderBy = OrderByType<Post>;

function findPublished(where: WhereType<Post>): Promise<Post[]> {
  return r.posts.findMany({ where: { ...where, published: true } });
}

DotPaths

All valid dot-notation paths for orderBy and aggregate groupBy:

type UserPaths = DotPaths<InferModel<typeof r, 'users'>>;
// "id" | "firstName" | "fullName" | "postsCount"
// | "orderSummary.totalAmount" | "orderSummary.orderCount"
// | "posts.title" | "posts.author.fullName" | ...

From client (alternative)

Extract types directly from client method signatures:

import type { InferEntityOrderBy, InferEntitySelect, InferEntityWhere } from '@relayerjs/drizzle';

type UserWhere = InferEntityWhere<typeof r, 'users'>;
type UserSelect = InferEntitySelect<typeof r, 'users'>;
type UserOrderBy = InferEntityOrderBy<typeof r, 'users'>;

Equivalent to InferModel + WhereType/SelectType/OrderByType but with two generic parameters.

API handler example

type User = InferModel<typeof r, 'users'>;

app.get('/users', async (req, res) => {
  const where: WhereType<User> = req.query.filter;
  const orderBy: OrderByType<User> = req.query.sort;
  const users = await r.users.findMany({ where, orderBy });
  res.json(users);
});