Update with Adding a Relation¶
The Deep Save API can be used to update an existing object and set a relation with a new child (or parent). Consider the examples below:
Existing Parent and New Child¶
This example retrieves an existing parent object (Order
) and uses the Deep Save API to perform the following:
- Save new child object (
OrderItem
) - Establish relationship between the
Order
and the newOrderItem
.
The Order
object already has two related OrderItem
objects before the sample code below runs:
Important
When working with relationships, the Deep Save API applies the "accumulation" policy. This means the following: if a parent object in the database already has some related objects and you update the object with new child objects in the relation, these objects will be added to the relation.
curl \
-H Content-Type:application/json \
-X PUT \
-d "{
\"objectId\":\"479090D2-5E85-48AB-B959-3FA14859A222\",
\"orderItems\":[
{
\"name\":\"Grapes\",
\"price\":3.99
}
]
}" \
-v https://xxxx.backendless.app/api/data/Product/deep-save
Server response:
{
"___class": "Order",
"ownerId": null,
"orderItems": [
{
"created": 1624093599000,
"price": 3.99,
"name": "Grapes",
"___class": "OrderItem",
"ownerId": null,
"updated": null,
"objectId": "BB0A82BA-D108-406C-A898-3064E566E6F2"
}
],
"updated": null,
"objectId": "479090D2-5E85-48AB-B959-3FA14859A222",
"created": 1624093011000
}
Codeless reference:
After the code runs, the new OrderItem
object is saved in the database and the Order
object relation is expanded to include it: