How to merge two JSON payload in Mule 4 Dataweave

How to combine two JSON payload in Mule 4 Dataweave 2.0

Consider a scenario where you might need to merge or combine two JSON arrays & send it as a response. In this case, we need to merge the data using a common key available in both messages.

Merge two JSON array into a single JSON array using Dataweave 2.0

Input 1:

{
  "users": [
    {
      "userId": 1,
      "firstName": "Uday",
      "lastName": "Kiran",
	  "role": "Developer",
      "phoneNumber": "930293029",
      "emailAddress": "hello@designgrows.com"
      
    },
   { 
       "userId": 2,
      "firstName": "Jake",
      "lastName": "Anderson",
	  "role": "Developer",
      "phoneNumber": "7567567567",
      "emailAddress": "jake@google.com"
   }
  ]
}

Input 2:

"skillsList": [
        {
          "skillID": 1,
          "skillName": "MuleSoft"
        },
        {
          "skillID": 2,
          "skillName": "Java"
        }
      ]

Expected Output:

[
  {
    "userId": 1,
    "firstName": "Uday",
    "skillName": "MuleSoft"
  },
  {
    "userId": 2,
    "firstName": "Jake",
    "skillName": "Java"
  }
]

Also see: Importing a Mapping File in a DataWeave Script of Mule

Combine two JSON array fields into one JSON array using Dataweave 2.0

Dataweave Code:

payload.users map (key,val)-> {
    "userId": key.userId,
    "firstName": key.firstName, 
(skills.skillsList filter ($."skillID" == key."userId")  map ((k,v) -> {
skillName: k.skillName

}))

}

Output:

Also read: Simple use of filter, contains in Dataweave 2.0 on JSON message