Overview

The "Deep Save" functionality is a single API request that can create or update a complete "object tree" in the database using a single transaction. The object tree starts with the root object and includes other child objects, their corresponding children and so on. Consider the following object diagram:

There is a parent object of type Person, the object has a relation through the homeAddress property to an Address object. Using the Deep Save functionality, you can perform the following operations with a single API call:

• Save new Person and the related Address in the database. Both objects will be saved in the corresponding tables and a relationship at the database level will be created between them.
• Update existing Person in the database with a new related Address object. The new Address object will be stored in the corresponding table and the relationship will be created in the database.
• Update both Person and Address objects in the database.

Important

Since the Deep Save API uses Backendless transactions, the tables/schema where the data is being saved must be created before the API is used. This requirement stems from the Transaction API that requires the schema to be pre-created.

Consider the example below. The example stores a new Person and the related Address objects in the database using the Deep Save API:

Using Untyped ObjectsCustom Class/Function

const person = {
  name: 'Bob',
  age : 30
}

const address = {
  city   : 'New York',
  country: 'USA'
}

person.homeAddress = address

Backendless.Data.of('Person').deepSave(person)
  .then(savedObject => console.log('Person and Address objects have been saved: ', savedObject))
  .catch(error => console.log('Server reported an error: ', error))

const person = new Person({ name: 'Bob', age: 30 })
const address = new Address({ city: 'New York', country: 'USA' })

person.homeAddress = address

Backendless.Data.of(Person).deepSave(person)
  .then(savedObject => console.log('Person and Address objects have been saved: ', savedObject))
  .catch(error => console.log('Server reported an error: ', error))

Person class:

class Person {
  constructor(data) {
    data = data || {}

    this.name = data.name
    this.age = data.age
    this.homeAddress = data.homeAddress
  }
}

Address class:

class Address {
  constructor(data) {
    data = data || {}

    this.city = data.city
    this.country = data.country
  }
}

Once the code runs, you will find the following two objects in the database. Notice that a single deep-save API call resulted in both objects saved in the corresponding tables and a relationship in the homeAddress column in the Person table points to the Address object:

Person table:

Address table: