Filter an Array of Object in DataWeave use for Mulesoft

Question

Can anyone let me know how can I transform this input json I have tried with below transformation but didn't worked.

I have tried to used filter function and groupBy function, but for Multiple output it is failing the testCase.

tried with this method `

%dw 2.0
output application/json
---
payload.Bd map (val,index) ->{
    "d23": val,
    "lt":(payload.output2 filter(payload.Bd contains val) map(Value) -> 
    {
        Val34: Value.PId
        }
    )
         
}

input -

[
  {
    "Val34": "968",
    "d23": "Y1"
  },
  {
    
    "Val34": "958",
    "d23": "Y2"
  },
  {
    
    "Val34": "951",
    "d23": "Y2"
  }
]

expected output -

[
  {
    "d23": "Y1",
    "lt": [
      {
        "Val34": "968"
      }
    ]
  },
  {
    "d23": "Y2",
    "lt": [
      {
        "Val34": "958"
      },
      {
        "Val34": "951"
      }
    ]
  }
]

`

Answer 1

You can try first groupingBy 2nd key value pair.. I assumed "d23": "Y1", "d23": "Y3" will be in position index[1] .

Further you can map on grouped elements and access index[0]

%dw 2.0
output application/json
---
(payload groupBy ((item, index) -> item[1])) pluck $ map{
    ($[0][&1]),
    "lt": ($ map(it,in)->(it[&0]))
}

Sample Input

[
  {
    "Val34": "968",
    "d23": "Y1"
  },
   {
    "Val34": "998",
    "d23": "Y3"
  },

       {
    "Val34": "988",
    "d23": "Y1"
  },
  {
    
    "Val34": "958",
    "d23": "Y2"
  },
  {
    
    "Val34": "951",
    "d23": "Y2"
  }
]

Output

[
  {
    "d23": "Y1",
    "lt": [
      {
        "Val34": "968"
      },
      {
        "Val34": "988"
      }
    ]
  },
  {
    "d23": "Y3",
    "lt": [
      {
        "Val34": "998"
      }
    ]
  },
  {
    "d23": "Y2",
    "lt": [
      {
        "Val34": "958"
      },
      {
        "Val34": "951"
      }
    ]
  }
]

Answer 2

Group by d23 values and map all the rest:

%dw 2.0
output application/json
---
payload groupBy ((item, index) -> item.d23) pluck {
    d23: $[0].d23,
    lt: ($.Val34 map (l,indOfl) -> {Val34: l})
}