AWS documentdb documentation change

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

File: documentdb/latest/developerguide/cmp.md

Summary

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

Security assessment

This change adds general documentation for a database operator ($cmp) without any mention of security vulnerabilities, patches, or security features. The connection strings in examples include TLS parameters (tls=true, tlsCAFile) which are standard security practices for encrypted connections, but this is routine security documentation rather than addressing a specific security issue.

Diff

diff --git a/documentdb/latest/developerguide/cmp.md b/documentdb/latest/developerguide/cmp.md
index 8b1378917..086f151dc 100644
--- a//documentdb/latest/developerguide/cmp.md
+++ b//documentdb/latest/developerguide/cmp.md
@@ -0,0 +1 @@
+[](/pdfs/documentdb/latest/developerguide/developerguide.pdf#cmp "Open PDF")
@@ -1,0 +3,152 @@
+[Documentation](/index.html)[Amazon DocumentDB](/documentdb/index.html)[Developer Guide](what-is.html)
+
+Example (MongoDB Shell)Code examples
+
+# $cmp
+
+The `$cmp` operator in Amazon DocumentDB is used to compare two values and return an integer value that indicates their relative order. It is a comparison operator that compares two expressions and returns an integer value of -1, 0, or 1, depending on whether the first value is less than, equal to, or greater than the second value, respectively.
+
+**Parameters**
+
+  * `expression1`: The first expression to compare.
+
+  * `expression2`: The second expression to compare.
+
+
+
+
+## Example (MongoDB Shell)
+
+The following example demonstrates the usage of the `$cmp` operator to compare two numeric values.
+
+**Create sample documents**
+    
+    
+    db.collection.insertMany([
+      { _id: 1, value1: 10, value2: 20 },
+      { _id: 2, value1: 15, value2: 15 },
+      { _id: 3, value1: 20, value2: 10 }
+    ]);
+
+**Query example**
+    
+    
+    db.collection.find({
+      $expr: {
+        $cmp: ["$value1", "$value2"]
+      }
+    })
+
+**Output**
+    
+    
+    [
+      { "_id" : 1, "value1" : 10, "value2" : 20 },
+      { "_id" : 3, "value1" : 20, "value2" : 10 }
+    ]
+
+In this example, the `$cmp` operator compares the `value1` and `value2` fields for each document. The result is:
+    
+    
+    - `$cmp: ["$value1", "$value2"]` returns -1 for the first document (10 < 20), 0 for the second document (15 = 15), and 1 for the third document (20 > 10).
+
+## Code examples
+
+To view a code example for using the `$cmp` command, choose the tab for the language that you want to use:
+
+Node.js
+    
+
+Here's an example of using the `$cmp` operator in a Node.js application with the `mongodb` driver:
+    
+    
+    const { MongoClient } = require('mongodb');
+    
+    const client = new MongoClient('mongodb://<username>:<password>@<cluster-endpoint>:27017/?tls=true&tlsCAFile=global-bundle.pem&replicaSet=rs0&readPreference=secondaryPreferred&retryWrites=false');
+    
+    async function main() {
+      await client.connect();
+      const db = client.db('test');
+      const collection = db.collection('mycollection');
+    
+      // Insert sample documents
+      await collection.insertMany([
+        { _id: 1, value1: 10, value2: 20 },
+        { _id: 2, value1: 15, value2: 15 },
+        { _id: 3, value1: 20, value2: 10 }
+      ]);
+    
+      // Query using $cmp operator
+      const result = await collection.find({
+        $expr: {
+          $cmp: ['$value1', '$value2']
+        }
+      }).toArray();
+    
+      console.log(result);
+    
+      await client.close();
+    }
+    
+    main();
+
+Python
+    
+
+Here's an example of using the `$cmp` operator in a Python application with the `pymongo` driver:
+    
+    
+    from pymongo import MongoClient
+    
+    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['mycollection']
+    
+    # Insert sample documents
+    collection.insert_many([
+        {'_id': 1, 'value1': 10, 'value2': 20},
+        {'_id': 2, 'value1': 15, 'value2': 15},
+        {'_id': 3, 'value1': 20, 'value2': 10}
+    ])
+    
+    # Query using $cmp operator
+    result = list(collection.find({
+        '$expr': {
+            '$cmp': ['$value1', '$value2']
+        }
+    }))
+    
+    print(result)
+    
+    client.close()
+
+The output of both the Node.js and Python examples will be the same as the MongoDB Shell example:
+    
+    
+    [
+      { "_id" : 1, "value1" : 10, "value2" : 20 },
+      { "_id" : 2, "value1" : 15, "value2" : 15 },
+      { "_id" : 3, "value1" : 20, "value2" : 10 }
+    ]
+
+![Warning](https://d1ge0kk1l5kms0.cloudfront.net/images/G/01/webservices/console/warning.png) **Javascript is disabled or is unavailable in your browser.**
+
+To use the Amazon Web Services Documentation, Javascript must be enabled. Please refer to your browser's Help pages for instructions.
+
+[Document Conventions](/general/latest/gr/docconventions.html)
+
+$changeStream
+
+$collStats
+
+Did this page help you? - Yes
+
+Thanks for letting us know we're doing a good job!
+
+If you've got a moment, please tell us what we did right so we can do more of it.
+
+Did this page help you? - No
+
+Thanks for letting us know this page needs work. We're sorry we let you down.
+
+If you've got a moment, please tell us how we can make the documentation better.