outerJoin

DataWeave 2.2 is compatible and bundled with Mule 4.2. Standard Support for Mule 4.2 ended on May 2, 2021, and this version of Mule will reach its End of Life on May 2, 2023, when Extended Support ends.

Deployments of new applications to CloudHub that use this version of Mule are no longer allowed. Only in-place updates to applications are permitted.

MuleSoft recommends that you upgrade to the latest version of Mule 4 that is in Standard Support so that your applications run with the latest fixes and security enhancements.

outerJoin(Array<L>, Array<R>, (leftValue: L) -> String, (rightValue: R) -> String): Array<{ l?: L, r?: R }>

Joins two array of objects by a given ID criteria.

outerJoin returns an array with all the left items, merged by ID with the right items in cases where any exist, and it returns right items that are not present in the left.

Introduced in DataWeave 2.2.0. Supported by Mule 4.2 and later.

Parameters

Name Description

left

The left-side array of objects.

right

The right-side array of objects.

leftCriteria

The criteria used to extract the ID for the left collection.

rightCriteria

The criteria used to extract the ID for the right collection.

Example

This example shows how join behaves. Notice that the output includes objects where the values of the input user.id and product.ownerId match, and it includes objects where there is no match for the value of the user.id or product.ownerId.

Source

 %dw 2.0
 import * from dw::core::Arrays
 var users = [{id: "1", name:"Mariano"},{id: "2", name:"Leandro"},{id: "3", name:"Julian"},{id: "5", name:"Julian"}]
 var products = [{ownerId: "1", name:"DataWeave"},{ownerId: "1", name:"BAT"}, {ownerId: "3", name:"DataSense"}, {ownerId: "4", name:"SmartConnectors"}]
 output application/json
 ---
 outerJoin(users, products, (user) -> user.id, (product) -> product.ownerId)

Output

[
  {
    "l": {
      "id": "1",
      "name": "Mariano"
    },
    "r": {
      "ownerId": "1",
      "name": "DataWeave"
    }
  },
  {
    "l": {
      "id": "1",
      "name": "Mariano"
    },
    "r": {
      "ownerId": "1",
      "name": "BAT"
    }
  },
  {
    "l": {
      "id": "2",
      "name": "Leandro"
    }
  },
  {
    "l": {
      "id": "3",
      "name": "Julian"
    },
    "r": {
      "ownerId": "3",
      "name": "DataSense"
    }
  },
  {
    "l": {
      "id": "5",
      "name": "Julian"
    }
  },
  {
    "r": {
      "ownerId": "4",
      "name": "SmartConnectors"
    }
  }
]

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