Apache NiFi RecordPath Guide
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Child Operator

The RecordPath language is structured in such a way that we are able to easily reference fields of the outer-most Record, or fields of a child Record, or descendant Record. To accomplish this, we separate the names of the children with a slash character (/), which we refer to as the child operator. For example, let's assume that we have a Record that is made up of two fields: name and details. Also, assume that details is a field that is itself a Record and has two Fields: identifier and address. Further, let's consider that address is itself a Record that contains 5 fields: number, street, city, state, and zip. An example, written here in JSON for illustrative purposes may look like this:

        "name": "John Doe",
        "details": {
                "identifier": 100,
                "address": {
                        "number": "123",
                        "street": "5th Avenue",
                        "city": "New York",
                        "state": "NY",
                        "zip": "10020"

We can reference the zip field by using the RecordPath: /details/address/zip. This tells us that we want to use the details field of the "root" Record. We then want to reference the address field of the child Record and the zip field of that Record.