Get started with Dexie in Vue

1. Create a Vue project

Here we refer to Vue's own Getting Started page.

2. Install dexie

npm install dexie

3. Create a file `db.js` (or `db.ts`)

Applications typically have one single Dexie instance declared as its own module. This is where you declare which tables you need and how each table shall be indexed. A Dexie instance is a singleton throughout the application - you do not need to create it on demand. Export the resulting db instance from your module so that components or other modules can use it to query or write to the database.

// db.js
import Dexie from 'dexie';

export const db = new Dexie('myDatabase');
db.version(1).stores({
  friends: '++id, name, age', // Primary key and indexed props
});

Using Typescript?

If you use Typescript, table properties (such as db.friends) needs to be explicitly declared on a subclass of Dexie just to help out with the typings for your db instance, its tables and entity models.

// db.ts
import Dexie, { Table } from 'dexie';

export interface Friend {
  id?: number;
  name: string;
  age: number;
}

export class MySubClassedDexie extends Dexie {
  // 'friends' is added by dexie when declaring the stores()
  // We just tell the typing system this is the case
  friends!: Table<Friend>; 

  constructor() {
    super('myDatabase');
    this.version(1).stores({
      friends: '++id, name, age' // Primary key and indexed props
    });
  }
}

export const db = new MySubClassedDexie();

4. Create a component that adds some data

Writing to the database can be done using Table.add(), Table.put(), Table.update() and Collection.modify() - see Dexie's quick reference for examples. Here we're gonna create a simple Vue component that allows the user to add friends into the database using Table.add().

<!-- FriendAdder.vue -->
<template>
  <fieldset>
    <legend>Add new friend</legend>
    <label>
      Name:
      <input v-model="friendName" type="text" />
    </label>
    <br />
    <label>
      Age:
      <input v-model="friendAge" type="number" />
    </label>
    <br />
    <button @click="addFriend">Add Friend</button>
    <p>{{ status }}</p>
  </fieldset>
</template>

<script>
import { db } from '../db';

export default {
  name: 'FriendAdder',
  props: {
    defaultAge: {
      type: Number,
      default: 21,
    },
  },
  data: () => {
    return {
      status: '',
      friendName: '',
      friendAge: this.defaultAge,
    };
  },
  methods: {
    async addFriend() {
      try {
        // Add the new friend!
        const id = await db.friends.add({
          name: this.friendName,
          age: this.friendAge,
        });

        this.status = `Friend ${this.friendName}
          successfully added. Got id ${id}`;

        // Reset form:
        this.friendName = '';
        this.friendAge = this.defaultAge;
      } catch (error) {
        this.status = `Failed to add
          ${this.friendName}: ${error}`;
      }
    },
  },
};
</script>

5. Create a component that queries data

Write a simple component that just renders all friends in the database.

To be able to consume the observable returned from Dexie's liveQuery(), we need to manage its subscription and unsubscription. For this sample, we use the hook useObservable() from @vueuse/rxjs.

npm install rxjs
npm install @vueuse/rxjs

Note that there are other ways to consume observables in vue - such as manually subscribe and unsubscribe in the lifecycle hooks if you prefer.

<!-- FriendList.vue -->
<template>
  <ul>
    <li v-for="friend in friends" :key="friend.id">
      {{ friend.name }}, {{ friend.age }}
    </li>
  </ul>
</template>

<script>
  import { liveQuery } from "dexie";
  import { useObservable } from "@vueuse/rxjs";
  import { db } from "./db";

  export default {
    name: "FriendList",
    setup() {
      return {
        db,
        friends: useObservable(
          liveQuery(() => db.friends.toArray())
        ),
      };
    },
  };
</script>

To make more detailed queries, refer to Dexie's quick reference for querying items.