Mixed - Node.js SDK

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Realm Object Models

Create an Object With a Mixed Value
Collections as Mixed
Query for Objects with a Mixed Value

Atlas Device SDKs are deprecated. Refer to the deprecation page for details.

Changed in version 12.9.0: Mixed properties can contain lists or dictionaries of mixed data.

New in version 10.5.0.

The mixed data type is a realm property type that can hold any valid Realm data type except an embedded object or a set. You can create collections (lists, sets, and dictionaries) of type mixed. Properties using the mixed data type can also hold null values.

Note

The mixed data type is indexable, but you can't use it as a primary key. Because null is a permitted value, you can't declare a Mixed property as optional.

Realm Object Models

To set a property of your object model as mixed, set the property's type to "mixed".

const DogSchema = {
  name: "Dog",
  properties: {
    name: "string",
    birthDate: "mixed",
  },
};

Create an Object With a Mixed Value

Create an object with a mixed value by running the realm.create() method within a write transaction.

realm.write(() => {
  // create a Dog with a birthDate value of type string
  realm.create("Dog", { name: "Euler", birthDate: "December 25th, 2017" });
  // create a Dog with a birthDate value of type date
  realm.create("Dog", {
    name: "Blaise",
    birthDate: new Date("August 17, 2020"),
  });
  // create a Dog with a birthDate value of type int
  realm.create("Dog", {
    name: "Euclid",
    birthDate: 10152021,
  });
  // create a Dog with a birthDate value of type null
  realm.create("Dog", {
    name: "Pythagoras",
    birthDate: null,
  });
});

Collections as Mixed

In SDK v12.9.0 and later, a mixed data type can hold collections (a list or dictionary, but not a set) of mixed elements. You can use mixed collections to model unstructured or variable data. For more information, refer to Define Unstructured Data.

You can nest mixed collections up to 100 levels.
You can query mixed collection properties and register a listener for changes, as you would a normal collection.
You can find and update individual mixed collection elements
You cannot store sets or embedded objects in mixed collections.

To use mixed collections, define the mixed type property in your data model. Then, create the list or dictionary collection.

Query for Objects with a Mixed Value

Query for objects with a mixed value by running the Collection.filtered() method and passing in a filter for a non-mixed field. You can then print the value of the mixed property or the entire object itself.

// To query for Blaise's birthDate, filter for his name to retrieve the realm object.
// Use dot notation to access the birthDate property.
let blaiseBirthDate = realm.objects("Dog").filtered(`name = 'Blaise'`)[0]
  .birthDate;
console.log(`Blaise's birth date is ${blaiseBirthDate}`);

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