# defineResource \[Tie a Drizzle table to an rxfy model] `defineResource` — from `rxfy-server-drizzle` — ties a Drizzle `PgTable` to an rxfy `ModelDescriptor`. You can either supply a pre-made model (the common case when sharing models between server and client) or let the package derive one automatically via `drizzle-zod`. :::note\[In-memory apps use `defineCollection`] An app without Drizzle uses `defineCollection({ name, model, seed? })` from `rxfy-server-memory` instead — it returns a resource whose binding is an in-memory `Map` (with `.all()` / `.get(id)`), paired with `memoryStorage()` on [`createSync`](/framework/server/create-server). ::: A resource pairs a `model` (from [`createModel`](/rxfy/create-model)) with a Drizzle `table` (a `pgTable`). The tabs below show both sides: :::code-group ```ts [src/blog/resources.ts] import { commentModel, postModel, userModel } from "./models.js"; import { createResourceRegistry } from "rxfy-server"; import { defineResource } from "rxfy-server-drizzle"; import { comments, posts, users } from "../db/schema.js"; export const userResource = defineResource({ table: users, model: userModel }); export const postResource = defineResource({ table: posts, model: postModel }); export const commentResource = defineResource({ table: comments, model: commentModel }); export const resources = createResourceRegistry([userResource, postResource, commentResource]); ``` ```ts [src/blog/models.ts] import { createModel } from "rxfy"; import { z } from "zod"; // Branded ids keep post/user/comment ids from being mixed up — and are why the // writers need a raw-row cast (see Writes). const UserIdSchema = z.string().brand("UserId"); const PostIdSchema = z.string().brand("PostId"); const CommentIdSchema = z.string().brand("CommentId"); const UserSchema = z.object({ id: UserIdSchema, name: z.string(), email: z.string() }); const PostSchema = z.object({ id: PostIdSchema, userId: UserIdSchema, title: z.string(), body: z.string() }); const CommentSchema = z.object({ id: CommentIdSchema, postId: PostIdSchema, name: z.string(), body: z.string() }); export const userModel = createModel({ schema: UserSchema, getKey: (x) => x.id, name: "user" }); export const postModel = createModel({ schema: PostSchema, getKey: (x) => x.id, name: "post" }); export const commentModel = createModel({ schema: CommentSchema, getKey: (x) => x.id, name: "comment" }); ``` ```ts [src/db/schema.ts] import { pgTable, text, timestamp } from "drizzle-orm/pg-core"; export const users = pgTable("users", { id: text("id").primaryKey(), name: text("name").notNull(), email: text("email").notNull(), }); export const posts = pgTable("posts", { id: text("id").primaryKey(), userId: text("user_id").notNull(), title: text("title").notNull(), body: text("body").notNull(), createdAt: timestamp("created_at").notNull().defaultNow(), }); export const comments = pgTable("comments", { id: text("id").primaryKey(), postId: text("post_id").notNull(), name: text("name").notNull(), body: text("body").notNull(), createdAt: timestamp("created_at").notNull().defaultNow(), }); ``` ::: **Name resolution** — `name` defaults to `model.name` when a model is supplied, then falls back to the SQL table name. It becomes the topic namespace used for sync routing (`"posts:uuid-..."`) and must match the rxfy model's own `name` so `patch` messages land in the right client store. **`primaryKeyColumn`** — `defineResource` calls `primaryKeyColumn(table)` internally to locate the single `primary: true` column. Composite primary keys are not supported in v1; the function throws if it finds more than one PK column or a `primaryKeys`-style composite key. ## createResourceRegistry `createResourceRegistry` — from core `rxfy-server` — indexes resources by name, rejects duplicates, and exposes `byName`, `model`, and `all`. It is a neutral convenience lookup: [`createSync`](/framework/server/create-server) does not require it, since the writers take a resource directly. `createResourceRegistry` lives in core `rxfy-server`; `defineResource` comes from `rxfy-server-drizzle`, and `defineCollection` from `rxfy-server-memory`.