How to use shift and modify-overwrite-beta in jolt

Question

I want to know how to use shift and modify-overwrite-beta for the below input. Please explain how it works with your answer.

Input:

[
  {
    "data": {
      "firstName": "Leanne",
      "lastName": "Graham",
      "id": 111
    }
  },
  {
    "data": {
      "firstName": "Ervin",
      "lastName": "Howell",
      "id": 222
    }
  }
]

Desired output:

{
  "111": {
    "fullName": "Leanne Graham"
  },
  "222": {
    "fullName": "Ervin Howell"
  }
}

Mohammadreza Khedri · Accepted Answer · 2023-01-25T11:11:43.343

You can solve that in different ways.

1. This spec is more understandable:

Order your list with the id value as a key in the shift operation: @(1,id)
Concat firstName and lastName in the modify-overwrite-beta operation: =concat(@(1,firstName),' ',@(1,lastName))
Remove unused keys in the remove operation: id, firstName, lastName

[
  {
    "operation": "shift",
    "spec": {
      "*": { // index of the array: 1, 2
        "*": { // data object
          "*": "@(1,id).&" // value of id in the current object: 111, 222
        }
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": { // ids: 111, 222
        "fullName": "=concat(@(1,firstName),' ',@(1,lastName))"
      }
    }
  },
  {
    "operation": "remove",
    "spec": {
      "*": { // ids: 111, 222
        "id": "",
        "firstName": "",
        "lastName": ""
      }
    }
  }
]

2. This spec is shorter:

Concat firstName and lastName in the modify-overwrite-beta operation: =concat(@(1,firstName),' ',@(1,lastName))
Get the value of id as a key and put fullname in it: key @(1,id).fullName, value @(0,fullName)

[
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "*": {
          "fullName": "=concat(@(1,firstName),' ',@(1,lastName))"
        }
      }
    }
  },
  {
    "operation": "shift",
    "spec": {
      "*": {
        "*": {
          "@(0,fullName)": "@(1,id).fullName"
        }
      }
    }
  }
]

The following image can help more:

When you want to use the value of a key, you can use `@` RHS in the jolt. for this one, it's mean of **`@(1)`**: get parent object and **`@(1,id)`**: get id from parent object. — Mohammadreza Khedri, Jan 25 '23 at 10:54

Barbaros Özhan · Answer 2 · 2023-01-25T13:59:22.040

You can use those consecutive transformation specs

[
  {
    "operation": "shift",
    "spec": {
      "*": {// represents the level of the outermost object
        "*": {// represents the level of the "data" object
          "*": "@1,id.&"//make "id" values key of each object, "&" replicates each attribute's values
        }
      }
    }
  },
  {
    "operation": "modify-overwrite-beta",
    "spec": {
      "*": {
        "FullName": "=concat(@(1,firstName),' ',@(1,lastName))"// concatenate attributes through adding 1 level deep shift of the tree as staying on the right hand side, and name by the literal "FullName" on the left hand side
      }
    }
  },
  {
    "operation": "remove",
    "spec": {
      "*": {
        "fi*Name|la*Name|id": "" //delete attributes "id" and the ones ending with "Names" except for the "fullName"
      }
    }
  }
]

as the names suggest shift is used to move the attributes/arrays/objects to their new places, and modify updates on the existing structure

How to use shift and modify-overwrite-beta in jolt

2 Answers2