Created question in FIWARE Q/A platform on 18-09-2019 at 10:09
Please, ANSWER this question AT https://stackoverflow.com/questions/57987944/how-to-add-timeinstant-creationdate-and-modifieddate-into-cratedb-with-orion-co

Question:
How to add TimeInstant, CreationDate and ModifiedDate into CrateDB with Orion Context Broker?

Description:
I'm setting up a Firmware-Framework, where I unforutunately have to add historically Sensor Values. But I also need the creationDate and the modificationDate for other usecases.

Therefore I add the Attribute "Metadata" with the variable "TimeInstant". Then I create an Entity, create an Orion-Subscription for that Entity and update the Entity with my old Sensor-Valses.

The Json-File I send to the Orion-Context Broker to update the Attribute looks like this:

{
"metadata": {
"TimeInstant":

},
"type": "Number",
"value": 0.0132361 }

The Output in my Mongo-DB like this:

"_id":

,
"attrNames": [
"Sensor_value"
],
"attrs": {
"Sensor_value": {
"value": 0.01632361,
"type": "Number",
"md": {
"TimeInstant":

},
"mdNames": [
"TimeInstant"
],
"creDate": 1568712813,
"modDate": 1568735930
}
},
"creDate": 1568712813,
"modDate": 1568735930,
"lastCorrelator": "0a129232-d964-11e9-8e5a-0242ac130009" }

But my Crate-DB only has the columns:
entity_id entity_type fiware_servicepath sensor_value time_index

My Subscription File looks like this:

{
"expires": "2019-12-24T18:00:00",
"notification": {
"http":

,
"metadata": [
"dateCreated",
"dateModified",
"TimeInstant"
]
},
"subject": {
"entities": [

]
},
"throttling": 0 }

I've tried changing the "Metadata" Attributes in the Subscription-File, also tried restartig Crate-DB, ContextBroker e.g..

I excpect the CrateDb to show all three values: "dateCreated", "dateModified" and "TimeInstant".