Jolt Transformation to "unpivot" repeating columns into nested JSON array - json

Question

My source data is a huge flatten CSV which contains data that I'd like to normalise and store in a number of separate database tables. I'm wondering if I can use a JOLT transformation to alter the structure of my CSV data which I've already a flat JSON object.
For example, the object below has two 'parent' rows and three repeating pairs of columns which are the 'child' rows:
{
"id": 1,
"name": "zzz",
"code_1": "abc",
"date_1": "2021-01-01",
"code_2": "def",
"date_2": "2021-01-02",
"code_3": "ghi",
"date_3": "2021-01-03"
}
Can I use JOLT to generate the output:
{
"id": 1,
"name": "zzz",
"codes": [
{
"code": "abc",
"date": "2021-01-01"
},
{
"code": "def",
"date": "2021-01-02"
},
{
"code": "ghi",
"date": "2021-01-03"
}
]
}
I've had a play around with the Jolt Playground, but as yet I've not found something which could achieve this goal.
Any hints, tips, or pointers welcome.
Thanks in advance.
UPDATE:
I'm getting closer, with the following spec and output. My codes and dates are in different objects however:
spec:
[
{
"operation": "shift",
"spec": {
"identifier": "id",
"name": "name",
"code*": "codes[].code",
"date*": "codes[].date"
}
}
]
output:
{
"id" : 1,
"name" : "zzz",
"codes" : [ {
"code" : "abc"
}, {
"date" : "2021-01-01"
}, {
"code" : "def"
}, {
"date" : "2021-01-02"
}, {
"code" : "ghi"
}, {
"date" : "2021-01-03"
} ]
}
(Edit: corrected the required output.)

Answer 1

You can use shift transformations twice as the elements are grouped under common numbered keys by _1,_2,_3 in the first step, and then remove keys of those objects while nesting them within codes list such as
[
{
"operation": "shift",
"spec": {
"*": "&",
"code*": { "#": "&(0,1).code" },
"date*": { "#": "&(0,1).date" }
}
},
{
"operation": "shift",
"spec": {
"_*": "codes[]",
"*": "&"
}
}
]