in nodered, as a rule f thumb you use msg.payload as the data you are working with and each node uses msg.payload as input and output.
If you need to save data that is not used by the next node, you save it somewhere else like msg.mydata
Changing that, is fine,but i highly recommend you do not do that, it will make it harder to read and troubleshoot your flows.
my api nodes always expect an array as input and gives an array back. For ease of use, if an api node received an object t converts it to an array and continues. So when you give the api update node a data it will fail, not sure why you was doing that ?
here is a basic example of how to insert and update an object
example workflow
[
{
"id": "1a904c0d8057d7e0",
"type": "inject",
"z": "562ba6bdfee8207a",
"name": "",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "",
"payloadType": "date",
"x": 200,
"y": 4260,
"wires": [
[
"577c268e71f1c871"
]
]
},
{
"id": "577c268e71f1c871",
"type": "api get",
"z": "562ba6bdfee8207a",
"name": "",
"query": "{\"_type\": \"mytest\"}",
"querytype": "str",
"projection": "",
"projectiontype": "str",
"top": 500,
"toptype": "num",
"skip": 0,
"skiptype": "num",
"collection": "entities",
"collectiontype": "str",
"resultfield": "payload",
"resultfieldtype": "msg",
"orderby": "",
"orderbytype": "str",
"x": 350,
"y": 4260,
"wires": [
[
"5c124d3afc02ec74"
]
]
},
{
"id": "11d0f40518266eaf",
"type": "inject",
"z": "562ba6bdfee8207a",
"name": "",
"props": [
{
"p": "payload"
},
{
"p": "topic",
"vt": "str"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "",
"payloadType": "date",
"x": 200,
"y": 4200,
"wires": [
[
"9a35681bbdca2f22"
]
]
},
{
"id": "94c92864069e1fb0",
"type": "api addorupdate",
"z": "562ba6bdfee8207a",
"name": "",
"writeconcern": "0",
"journal": "false",
"entitytype": "mytest",
"entitytypetype": "str",
"collection": "entities",
"collectiontype": "str",
"entities": "payload",
"entitiestype": "msg",
"uniqeness": "_type",
"uniqenesstype": "str",
"resultfield": "",
"inputfield": "",
"x": 540,
"y": 4200,
"wires": [
[
"ec7ec592fb74b023"
]
]
},
{
"id": "9a35681bbdca2f22",
"type": "function",
"z": "562ba6bdfee8207a",
"name": "function 86",
"func": "msg.payload = {name: \"my test\", _type: \"mytest\"}\nreturn msg;",
"outputs": 1,
"timeout": 0,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 350,
"y": 4200,
"wires": [
[
"94c92864069e1fb0"
]
]
},
{
"id": "93e513de68eb36d8",
"type": "api update",
"z": "562ba6bdfee8207a",
"name": "",
"entitytype": "",
"entitytypetype": "str",
"collection": "entities",
"collectiontype": "str",
"entities": "payload",
"entitiestype": "msg",
"writeconcern": "0",
"journal": "false",
"inputfield": "",
"resultfield": "",
"x": 690,
"y": 4260,
"wires": [
[
"51a26c9e8484d89b"
]
]
},
{
"id": "5c124d3afc02ec74",
"type": "function",
"z": "562ba6bdfee8207a",
"name": "function 87",
"func": "msg.payload.filter(item=> {\n item.name = item.name + \" updated\"\n})\nreturn msg;",
"outputs": 1,
"timeout": 0,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 510,
"y": 4260,
"wires": [
[
"93e513de68eb36d8"
]
]
},
{
"id": "ec7ec592fb74b023",
"type": "debug",
"z": "562ba6bdfee8207a",
"name": "debug 58",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload.0.name",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 720,
"y": 4200,
"wires": []
},
{
"id": "51a26c9e8484d89b",
"type": "debug",
"z": "562ba6bdfee8207a",
"name": "debug 59",
"active": true,
"tosidebar": true,
"console": false,
"tostatus": false,
"complete": "payload.0.name",
"targetType": "msg",
"statusVal": "",
"statusType": "auto",
"x": 860,
"y": 4260,
"wires": []
}
]