AWS documentdb documentation change

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

File: documentdb/latest/developerguide/set-stage.md

Summary

Added documentation for the $set aggregation stage in Amazon DocumentDB version 8.0, including syntax, parameters, MongoDB shell example, and code examples in Node.js and Python

Security assessment

This change adds documentation for a new aggregation operator ($set) in DocumentDB version 8.0. The content includes standard usage examples and code samples with connection strings that include TLS parameters (tls=true, tlsCAFile=global-bundle.pem). These TLS parameters are standard security practices for DocumentDB connections but are not newly introduced in this documentation. The change appears to be routine feature documentation for a new aggregation stage rather than addressing a specific security vulnerability or weakness.

Diff

diff --git a/documentdb/latest/developerguide/set-stage.md b/documentdb/latest/developerguide/set-stage.md
index 8b1378917..112e6370e 100644
--- a//documentdb/latest/developerguide/set-stage.md
+++ b//documentdb/latest/developerguide/set-stage.md
@@ -0,0 +1 @@
+[](/pdfs/documentdb/latest/developerguide/developerguide.pdf#set-stage "Open PDF")
@@ -1,0 +3,136 @@
+[Documentation](/index.html)[Amazon DocumentDB](/documentdb/index.html)[Developer Guide](what-is.html)
+
+Example (MongoDB Shell)Code examples
+
+# $set
+
+New from version 8.0
+
+Not supported by Elastic cluster.
+
+The `$set` aggregation stage in Amazon DocumentDB allows you to add new fields or update existing field values in documentation during an aggregation pipeline.
+
+**Parameters**
+
+  * `expression`: The expression to evaluate. This can be any valid aggregation expression, including field references and arithmetic operations.
+
+
+
+
+## Example (MongoDB Shell)
+
+The following example demonstrates the use of the `$set` aggregation stage to calculate totals by multiplying the `quantity` field by the `price` field.
+
+**Create sample documents**
+    
+    
+    db.inventory.insertMany([
+      { item: "pencil", quantity: 100, price: 0.24},
+      { item: "pen", quantity: 204, price: 1.78 }
+    ]);
+
+**Aggregation example**
+    
+    
+    db.inventory.aggregate([
+      {
+        $set: {
+          total: { $multiply: ["$quantity", "$price"] }
+        }
+      }
+    ])
+
+**Output**
+    
+    
+    [
+      {
+        _id: ObjectId('69248951d66dcae121d2950d'),
+        item: 'pencil',
+        quantity: 100,
+        price: 0.24,
+        total: 24
+      },
+      {
+        _id: ObjectId('69248951d66dcae121d2950e'),
+        item: 'pen',
+        quantity: 204,
+        price: 1.78,
+        total: 363.12
+      }
+    ]
+
+## Code examples
+
+To view a code example for using the `$set` 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 inventory = db.collection('inventory');
+    
+      const result = await inventory.aggregate([
+          {
+            $set: {
+              total: { $multiply: ["$quantity", "$price"] }
+            }
+          }
+      ]).toArray();
+    
+      console.log(result);
+      client.close();
+    }
+    
+    example();
+
+Python
+    
+    
+    
+    from pymongo import MongoClient
+    
+    def example():
+        client = MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false')
+        db = client['test']
+        inventory = db['inventory']
+    
+        result = list(inventory.aggregate([
+          {
+            "$set": {
+              "total": { "$multiply": ["$quantity", "$price"] }
+            }
+          }
+        ]))
+    
+        print(result)
+        client.close()
+    
+    example()
+
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+
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+
+[Document Conventions](/general/latest/gr/docconventions.html)
+
+$second
+
+$setDifference
+
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