Jolt Transform MapRecord to JSON - json

Question

I need to flatten a db using nifi. I read in a table based in a PK ID. For each row the nifi content is shown as a MapRecord. I need to pull each field value out of the MapRecord and make it a json property.
Input:
{
"maxResults": 150,
"total": 89,
"issues": "MapRecord[{issueId=1, firstName=Jack, lastName=Smith}]",
"address": "MapRecord[{addressId=1, street=Mockingbird Lane, town=Timbuktoo}]"
}
Notice in the MapRecord nothing is in quotes. I don't know why this is like this. It is obviously not JSON.
I want the result to look like:
Expected output:
{
"maxResults": 150,
"total": 89,
"firstName": "Jack",
"lastName": "Smith",
"street": "Mockingbird Lane",
"town": "Timbuktoo"
}
Does anyone know how to do this using a JOLT transform?
Thanks.

Answer 1

You can manage it to solve by applying too many transformation specs. In the first step need to extract the key-value pairs. In order to perform this split function within modify-overwrite-beta might be used. At the later steps, need to keep the existing pairs(maxResults&total) and properly combine with the extracted ones using some trick methods such as
[
{
"operation": "modify-overwrite-beta",
"spec": {
"i": "=split('}',#(1,issues))",
"a": "=split('}',#(1,address))"
}
},
{
"operation": "modify-overwrite-beta",
"spec": {
"i": "=split(', ',#(1,i))",
"a": "=split(', ',#(1,a))"
}
},
{
"operation": "shift",
"spec": {
"maxResults": "&",
"total": "&",
"i|a": {
"0": { "1|2": { "#": "theRest" } }
}
}
},
{
"operation": "shift",
"spec": {
"*": "arr0.&",
"theRest": { "*": "&" }
}
},
{
"operation": "modify-overwrite-beta",
"spec": {
"*": "=split('=',#(1,&))"
}
},
{
"operation": "shift",
"spec": {
"arr0": {
"*": {
"#": "arr[1]",
"$": "arr[0]"
}
},
"*": {
"*": {
"#": "arr.[&1]"
}
}
}
},
{
"operation": "shift",
"spec": {
"*": "&",
"arr": {
"0": null,
"*": {
"*": "[&1].#(2,[0].[&])"
}
}
}
},
{
"operation": "shift",
"spec": {
"0": null,
"*": ""
}
}
]