Mule 4（DataWeave 2.0）OuterJoin结果处理：扁平化及新增静态属性

Got it, let's get your DataWeave output into the exact format you need. The outerJoin gives us structured l (left array) and r (right array) objects, so we just need to flatten those, rename keys, add your static property, and tweak the structure.

First, let's address the typo in your expected output: the second object has "Key2": "2000" which I assume is a mistake (should be "Key1": "2000"). I'll provide two versions below—one that fixes that logical typo, and another if you actually need dynamic Key1, Key2, Key3 labels for the ID values.

Version 1: Logical Key Naming (Key1 for ID, Key2 for ID_2/EID) #

This matches what I think you intended, with consistent key names across all objects:

%dw 2.0
import * from dw::core::Arrays
output application/json
var var1 = [
 {"ID": 1000, "ID_2": "ABC-1000"},
 {"ID": 2000, "ID_2": "DEF-2000"},
 {"ID": 3000, "ID_2": "GHI-3000"}
]
var var2 = [
 {"EID": "ABC-1000", "GUID": "A0F4960AE5E54459A1B1FB40297EF893"},
 {"EID": "DEF-2000", "GUID": "63F6A192988A4C0696B117E9AC080611"},
 {"EID": "GHI-3000", "GUID": "A0FB600FA73E4E3BBF1CB59AA6E92AEF"}
]
---
outerJoin(var1, var2, (obj) -> obj.ID_2, (obj) -> obj.EID) map (joinResult) -> {
    Key1: joinResult.l.ID as String, // Convert ID to string as shown in expected output
    Key2: joinResult.l.ID_2,
    Name: "Test", // Static property
    GUID: joinResult.r.GUID
}

Output: #

[
{"Key1": "1000", "Key2": "ABC-1000", "Name": "Test", "GUID": "A0F4960AE5E54459A1B1FB40297EF893"},
{"Key1": "2000", "Key2": "DEF-2000", "Name": "Test", "GUID": "63F6A192988A4C0696B117E9AC080611"},
{"Key1": "3000", "Key2": "GHI-3000", "Name": "Test", "GUID": "A0FB600FA73E4E3BBF1CB59AA6E92AEF"}
]

Version 2: Dynamic Key Names (Key1, Key2, Key3 for IDs) #

If you actually need incrementing key names for the ID values (as shown in your expected output), use mapIndexed to generate dynamic keys:

%dw 2.0
import * from dw::core::Arrays
output application/json
var var1 = [
 {"ID": 1000, "ID_2": "ABC-1000"},
 {"ID": 2000, "ID_2": "DEF-2000"},
 {"ID": 3000, "ID_2": "GHI-3000"}
]
var var2 = [
 {"EID": "ABC-1000", "GUID": "A0F4960AE5E54459A1B1FB40297EF893"},
 {"EID": "DEF-2000", "GUID": "63F6A192988A4C0696B117E9AC080611"},
 {"EID": "GHI-3000", "GUID": "A0FB600FA73E4E3BBF1CB59AA6E92AEF"}
]
---
outerJoin(var1, var2, (obj) -> obj.ID_2, (obj) -> obj.EID) mapIndexed ((joinResult, index) -> {
    ("Key$(index + 1)"): joinResult.l.ID as String, // Dynamic key name
    Key2: joinResult.l.ID_2,
    Name: "Test",
    GUID: joinResult.r.GUID
})

Output: #

[
{"Key1": "1000", "Key2": "ABC-1000", "Name": "Test", "GUID": "A0F4960AE5E54459A1B1FB40297EF893"},
{"Key2": "2000", "Key2": "DEF-2000", "Name": "Test", "GUID": "63F6A192988A4C0696B117E9AC080611"},
{"Key3": "3000", "Key2": "GHI-3000", "Name": "Test", "GUID": "A0FB600FA73E4E3BBF1CB59AA6E92AEF"}
]

Key Changes Explained: #

• map/mapIndexed: Iterates over each join result to transform the structure.
• Key Renaming: Explicitly maps ID to your desired key name, and ID_2 to Key2.
• Static Property: Adds the hardcoded "Name": "Test" directly in the object.
• Type Conversion: Converts ID from a number to a string to match your expected output.

内容的提问来源于stack exchange，提问作者Triumph Spitfire