17. Replace Operation

Previously, users did not have the support to modify an existing NGSI-LD Entity by replacing all its attributes (properties or relationships). Users had to remove the existing entity and create a new one.

Replace Operation allows the modification of an existing NGSI-LD Entity by replacing all of the Attributes (Properties or Relationships). Replace Operation also allows the replacement of a single Attribute (Property or Relationship) within an NGSI-LD Entity.

As part this feature, we have provided following new operations:

• Replace entire entity: PUT <base url>/ngsi-ld/v1/entities/<entity-id>

• Replace entire Attribute: PUT <base url>/ngsi-ld/v1/entities/<entity-id>/attrs/<attr-id>

17.1. Example for Replace Operation

17.1.1. 1. Create Operation

In order to create the entity, we can hit the endpoint POST - http://<IP Address>:<port>/ngsi-ld/v1/entities/ with the given payload

{
    "id": "urn:ngsi-ld:Store:001",
    "type": "Store",
    "location": {
        "type": "GeoProperty",
        "value": {
            "type": "Point",
            "coordinates": [
                57.5522,
                -20.3484
            ]
        }
    },
    "address": {
        "type": "Property",
        "value": {
            "addressRegion": "Metropolis",
            "postalCode": "42420",
            "streetAddress": "Tiger Street 4",
            "addressLocality": "Cat City"
        }
    },
    "storeName": {
        "type": "Property",
        "value": "6-Stars"
    }
}

17.1.2. 2. Replace Operation

We can modify an existing NGSI-LD Entity by replacing all the Attributes (Properties or Relationships) without deleting the existing entity. For that we can hit the endpoint PUT - http://<IP Address>:<port>/ngsi-ld/v1/entities/urn:ngsi-ld:Store:001 with the given payload

{
    "id": "urn:ngsi-ld:Store:001",
    "type": "Store",
    "address": {
        "type": "Property",
        "value": {
            "streetAddress": "Tiger Street 2",
            "addressLocality": "Cat City",
            "postalCode": "42420"
        }
    },
    "storeName": {
        "type": "Property",
        "value": "Luxury Store"
    }
}

17.1.3. 3. Query Operation

In order to retrieve the Entity details after Replace operation, make a GET request with URL http://<IP Address>:<port>/ngsi-ld/v1/entities/urn:ngsi-ld:Store:001

Response:

{
    "id": "urn:ngsi-ld:Store:001",
    "type": "Store",
    "address": {
        "type": "Property",
        "value": {
            "streetAddress": "Tiger Street 2",
            "addressLocality": "Cat City",
            "postalCode": "42420"
        }
    },
    "storeName": {
        "type": "Property",
        "value": "Luxury Store"
    }
}

Here, after retrieving the entity, we can see that all the Attributes (Properties or Relationships) are modified without deleting the existing store entity.