Combine multiple json elements into array based on another json element value-CodePudding

I have been trying multiple approaches using JOLT to convert a Json as show below:

INPUT:

[
  {
    "CarOwners": [
      {
        "Name": "john",
        "car": "volvo"
      },
      {
        "Name": "john",
        "car": "Audi"
      },
      {
        "Name": "Mike",
        "car": "Audi"
      }
    ]
  }
]

OUTPUT:


[
  {
    "CarOwners": [
      {
        "Name": "john",
        "car": [
          "volvo",
          "Audi"
        ]
      },
      {
        "Name": "Mike",
        "car": ["Audi"]
      }
    ]
  }
]

To put it simply, based on owner name, I need to combine the json objects & make an array of car names & populate multiple values inside the list when a person owns more than 1 car. Is it even possible using JOLT? Can you please give a hint if you know? Thank you.

I tried to use shift operation but unfortunately unable to reach anywhere near the solution.

CodePudding user response：

Hi Anand this spec will resolve your query :

[
  {
    "operation": "shift",
    "spec": {
      "*": {
        "CarOwners": {
          "*": {
            "Name": {//If else condition to check Name is John
              "john": {
                "@(2,Name)": ".[#7].CarOwners.&1.Name", 
                "@(2,car)": "[#7].CarOwners.&1.car"
              },
              "Mike": {
                "@(2,Name)": "[#7].CarOwners.&1.Name",
                "@(2,car)": "[#7].CarOwners.&1.car"
              }
            }
          }
        }
      }
    }
 }, {
    "operation": "cardinality",
    "spec": {
      "*": {
        "CarOwners": {
          "*": {
            "Name": "ONE",
            "car": "MANY"
          }
        }
      }
    }
 }, {
    "operation": "shift",
    "spec": {
      "*": {
        "CarOwners": {
          "*": {
            "*": "[#5].CarOwners.[#2].&"
          }
        }
      }
    }
  }
]

CodePudding user response：

One option would be using two successive shift transformations such as

[
  {
    // group by Names to form individual objects
    "operation": "shift",
    "spec": {
      "*": { // the outermost level
        "*": { // for "CarOwners" array
          "*": { // the indexes of the array
            "car": "&2[&3].@(1,Name).&[]"
          }
        }
      }
    }
  },
  {
    // move object labels to the location of "Name" attribute values
    "operation": "shift",
    "spec": {
      "*": {
        "*": {
          "*": {
            "$": "&3[#2].Name",
            "car": "&3[#2].&"
          }
        }
      }
    }
  }
]

the demo on the site