Dexie

Dexie.js (Official home page: dexie.org) is a library that makes it super simple to use indexedDB - the standard client-side database in browsers. Read more about Dexie on it's README or at the home page.

Dexie is the main class and the default export of the library. An instance of this class represents an indexedDB database connection.

Syntax

var db = new Dexie(databaseName, options?);

Parameters

Parameter

Description

dbName: String

Database name

options: Object (optional)

API Options

Options

Option

Description

addons: Array

Explicitly define the addons to activate for this db instance

autoOpen: boolean

Default true. Whether database will open automatically on first query.

indexedDB:

Supply an alternate implementation of indexedDB. If supplying this, also supply IDBKeyRange that works with that implementation.

IDBKeyRange:

An implementation of the IDBKeyRange interface that works with provided indexedDB implementation.

allowEmptyDB: boolean

If opening in dynamic mode (not defining a schema) the call to db.open() will normally reject if the database didn't exist and this option is false or not set. By setting this option to true, Dexie.open() will succeed to create a new empty database when opening it dynamically.

modifyChunkSize: number

(since 3.1.0-alpha) Override the default value of 2000 rows per chunk used by Collection.modify(). See .

chromeTransactionDurability: 'default' | 'strict' | 'relaxed'

(since 3.2.0-beta.3) Override the default transaction durability in Chrome versions >=83. See

cache: 'cloned' | 'immutable' | 'disabled'

(since 4.0.1-alpha.17) Override the default caching behavior. Default is 'cloned' (dexie@>4 only) and allows optimistic updates to trigger liveQueries before transactions commit. 'immutable' also enables optimistic updates with some optimization - less cloning and less memory consumption but return values from read-operations from live queries are frozen. 'disabled' gives same behavior as dexie@3 with no cache or optimistic updates.

If the 'addons' option is omitted, it will default to the value of Dexie.addons.

Return Value

Dexie

Sample

// Declare db instance
var db = new Dexie("MyDatabase");

// Define Database Schema
db.version(1).stores({
  friends: "++id, name, age, isCloseFriend",
  notes: "++id, title, date, *items",
});

// Interact With Database
db.transaction("rw", db.friends, db.notes, function* () {
  // Let's add some data to db:
  var friend1Id = yield db.friends.add({
    name: "Camilla",
    age: 25,
    isCloseFriend: 1,
  });
  var friend2Id = yield db.friends.add({
    name: "Ban Ki-moon",
    age: 70,
    isCloseFriend: 0,
  });

  var noteId = yield db.notes.add({
    title: "Shop tomorrow",
    date: new Date(),
    items: ["milk", "butter"],
  });

  // Let's query the db
  var closeFriends = yield db.friends
    .where("isCloseFriend")
    .equals(1)
    .toArray();

  console.log("Close friends:" + closeFriends.map((f) => f.name));

  var toShop = yield db.notes
    .where("title")
    .startsWithIgnoreCase("shop")
    .toArray();

  console.log("Shopping list: " + toShop.map((note) => note.items));
}).catch(function (err) {
  // Catch any error event or exception and log it:
  console.error(err.stack || err);
});

Open sample in jsfiddle

Sample: Open existing database 'as is'

new Dexie("MyDatabase")
  .open()
  .then(function (db) {
    console.log("Found database: " + db.name);
    console.log("Database version: " + db.verno);
    db.tables.forEach(function (table) {
      console.log("Found table: " + table.name);
      console.log("Table Schema: " + JSON.stringify(table.schema, null, 4));
    });
  })
  .catch("NoSuchDatabaseError", function (e) {
    // Database with that name did not exist
    console.error("Database not found");
  })
  .catch(function (e) {
    console.error("Oh uh: " + e);
  });

Open sample in jsfiddle

Sample: Instantiate a Dexie with custom addon


// Define the addon
function myForEachAddon(db) {
    db.Collection.prototype.forEach = function (callback) {
        // Make the forEach() method just an alias of the existing
        // each() method:
        return this.each(callback);
    });
}
// Register it (optional)
Dexie.addons.push(myForEachAddon);

// Use it:
var db = new Dexie('dbname');
db.version(1).stores({friends: 'name'});
db.transaction('rw', db.friends, function () {
    db.friends.clear();
    db.friends.bulkAdd([{name: "Foo"},{name: "Bar"}]);
}).then(function() {
    db.friends
      .where('name')
      .anyOfIgnoreCase('foo','bar')
      .forEach(friend => {
          console.log(friend.name);
      });
}).catch(ex => {
    console.error(ex);
});

How options tells how to apply addons:

// Open normally. Registered addons will be invoked automatically.
var db1 = new Dexie("dbname");

// Explicitly tell Dexie to ignore registered addons:
var db2 = new Dexie("dbname", { addons: [] });

// Explicitly tell Dexie to use just your set of addons:
var db3 = new Dexie("dbname", { addons: [myForEachAddon] });