By Redis Team

Now that we have a client that's connected to Redis, we need to start mapping some persons. To do that, we need to define an Entity and a Schema. Let's start by creating a file named person.js in the om folder and importing client from client.js and the Entity and Schema classes from Redis OM:

import { Entity, Schema } from 'redis-om'
import client from './client.js'

Next, we need to define an entity. An Entity is the class that holds you data when you work with it—the thing being mapped to. It is what you create, read, update, and delete. Any class that extends Entity is an entity. We'll define our Person entity with a single line:

/* our entity */
class Person extends Entity {}

A schema defines the fields on your entity, their types, and how they are mapped internally to Redis. By default, entities map to JSON documents. Let's create our Schema in person.js:

/* create a Schema for Person */
const personSchema = new Schema(Person, {
  firstName: { type: 'string' },
  lastName: { type: 'string' },
  age: { type: 'number' },
  verified: { type: 'boolean' },
  location: { type: 'point' },
  locationUpdated: { type: 'date' },
  skills: { type: 'string[]' },
  personalStatement: { type: 'text' }
})

When you create a Schema, it modifies the Entity class you handed it (Person in our case) adding getters and setters for the properties you define. The type those getters and setters accept and return are defined with the type parameter as shown above. Valid values are: string, number, boolean, string[], date, point, and text.

The first three do exactly what you think—they define a property that is a String, a Number, or a Boolean. string[] does what you'd think as well, specifically defining an Array of strings.

date is a little different, but still more or less what you'd expect. It defines a property that returns a Date and can be set using not only a Date but also a String containing an ISO 8601 date or a Number with the UNIX epoch time in milliseconds.

A point defines a point somewhere on the globe as a longitude and a latitude. It creates a property that returns and accepts a simple object with the properties of longitude and latitude. Like this:

let point = { longitude: 12.34, latitude: 56.78 }

A text field is a lot like a string. If you're just reading and writing objects, they are identical. But if you want to search on them, they are very, very different. We'll talk about search more later, but the tl;dr is that string fields can only be matched on their whole value—no partial matches—and are best for keys while text fields have full-text search enabled on them and are optimized for human-readable text.

Now we have all the pieces that we need to create a repository. A Repository is the main interface into Redis OM. It gives us the methods to read, write, and remove a specific Entity. Create a Repository in person.js and make sure it's exported as you'll need it when we start implementing out API:

/* use the client to create a Repository just for Persons */
export const personRepository = client.fetchRepository(personSchema)

We're almost done with setting up our repository. But we still need to create an index or we won't be able to search. We do that by calling .createIndex(). If an index already exists and it's identical, this function won't do anything. If it's different, it'll drop it and create a new one. Add a call to .createIndex() to person.js:

/* create the index for Person */
await personRepository.createIndex()

That's all we need for person.js and all we need to start talking to Redis using Redis OM. Here's the code in its entirety:

import { Entity, Schema } from 'redis-om'
import client from './client.js'

/* our entity */
class Person extends Entity {}

/* create a Schema for Person */
const personSchema = new Schema(Person, {
  firstName: { type: 'string' },
  lastName: { type: 'string' },
  age: { type: 'number' },
  verified: { type: 'boolean' },
  location: { type: 'point' },
  locationUpdated: { type: 'date' },
  skills: { type: 'string[]' },
  personalStatement: { type: 'text' }
})

/* use the client to create a Repository just for Persons */
export const personRepository = client.fetchRepository(personSchema)

/* create the index for Person */
await personRepository.createIndex()

Now, let's add some routes in Express.