AWS documentdb documentation change

Service: documentdb · 2026-03-31 · Documentation low

File: documentdb/latest/developerguide/unwind.md

Summary

Added documentation for the $unwind operator in Amazon DocumentDB, including syntax, parameters, examples in MongoDB Shell, Node.js, and Python with connection strings

Security assessment

This change adds standard documentation for a MongoDB aggregation operator ($unwind) with code examples. The examples include TLS connection parameters (tls=true, tlsCAFile) which are standard security practices for DocumentDB connections, but this is not introducing new security features or addressing specific vulnerabilities. The change appears to be routine documentation addition for a database feature.

Diff

diff --git a/documentdb/latest/developerguide/unwind.md b/documentdb/latest/developerguide/unwind.md
index 8b1378917..ed781e853 100644
--- a//documentdb/latest/developerguide/unwind.md
+++ b//documentdb/latest/developerguide/unwind.md
@@ -0,0 +1 @@
+[](/pdfs/documentdb/latest/developerguide/developerguide.pdf#unwind "Open PDF")
@@ -1,0 +3,116 @@
+[Documentation](/index.html)[Amazon DocumentDB](/documentdb/index.html)[Developer Guide](what-is.html)
+
+Example (MongoDB Shell)Code examples
+
+# $unwind
+
+The `$unwind` operator is used to deconstruct an array field from the input documents to output a document for each element. This can be useful when you want to perform operations on the individual elements of an array, such as filtering, sorting, or transforming the data.
+
+**Parameters**
+
+  * `path`: The path to the array field to be unwound.
+
+  * `includeArrayIndex`: (optional) Specifies the name of the new field to hold the index of the array element.
+
+  * `preserveNullAndEmptyArrays`: (optional) Determines whether the operation keeps the original document when the array field is null or an empty array.
+
+
+
+
+## Example (MongoDB Shell)
+
+The following example demonstrates how to use the `$unwind` operator to deconstruct an array field and perform further operations on the individual elements.
+
+**Create sample documents**
+    
+    
+    db.people.insertMany([
+      { _id: 1, name: "jon", hobbies: ["painting", "dancing", "singing"] },
+      { _id: 2, name: "jane", hobbies: ["reading", "swimming"] },
+      { _id: 3, name: "jack", hobbies: [] }
+    ])
+
+**Query example**
+    
+    
+    db.people.aggregate([
+      { $unwind: "$hobbies" }
+    ])
+
+**Output**
+    
+    
+    [
+      { _id: 1, name: 'jon', hobbies: 'painting' },
+      { _id: 1, name: 'jon', hobbies: 'dancing' },
+      { _id: 1, name: 'jon', hobbies: 'singing' },
+      { _id: 2, name: 'jane', hobbies: 'reading' },
+      { _id: 2, name: 'jane', hobbies: 'swimming' }
+    ]
+
+## Code examples
+
+To view a code example for using the `$unwind` command, choose the tab for the language that you want to use:
+
+Node.js
+    
+    
+    
+    const { MongoClient } = require('mongodb');
+    
+    async function example() {
+      const client = await MongoClient.connect('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
+      const db = client.db('test');
+      const collection = db.collection('people');
+    
+      const result = await collection.aggregate([
+        { $unwind: '$hobbies' }
+      ]).toArray();
+    
+      console.log(result);
+      client.close();
+    }
+    
+    example();
+
+Python
+    
+    
+    
+    from pymongo import MongoClient
+    
+    def example():
+        client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
+        db = client['test']
+        collection = db['people']
+    
+        result = list(collection.aggregate([
+            { '$unwind': '$hobbies' }
+        ]))
+    
+        print(result)
+        client.close()
+    
+    example()
+
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+
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+
+[Document Conventions](/general/latest/gr/docconventions.html)
+
+$unset
+
+$vectorSearch
+
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