DOCSP-51823 Standardize Distinct usage example (#543)

* DOCSP-51823 Standardize Distinct usage example

* code comment fix

* NR review

* remaining review

* tech feedback

Author: lindseymoore

source/crud/query/distinct.txt

@@ -116,11 +116,37 @@ of the ``department`` field by using the ``Distinct()`` method:
 
       [English Geology]
 
+.. _golang-distinct-usage-example:
+
+Retrieve Distinct Values Example: Full File
+-------------------------------------------
+
+.. include:: /includes/usage-examples/example-intro.rst
+
+This example performs the following actions on the ``restaurant``
+collection:
+
+- Matches documents in which the value of the ``cuisine`` field is ``"Tapas"``
+- Returns distinct values of the ``borough`` field from the matched documents
+
+.. io-code-block::
+   :copyable: true
+
+   .. input:: /includes/usage-examples/code-snippets/distinct.go
+      :language: go
+      :dedent:
+
+   .. output::
+      :language: none
+      :visible: false
+
+      Brooklyn
+      Manhattan
+      Queens
+
 Additional Information
 ----------------------
 
-For a runnable example that retrieves distinct values, see :ref:`golang-distinct-usage-example`.
-
 To learn about constructing a query filter, see :ref:`golang-query-document`.
 
 API Documentation

source/includes/usage-examples/code-snippets/distinct.go

@@ -13,14 +13,24 @@ import (
 	"go.mongodb.org/mongo-driver/v2/mongo/options"
 )
 
+type Restaurant struct {
+	ID           bson.ObjectID `bson:"_id"`
+	Name         string
+	RestaurantId string `bson:"restaurant_id"`
+	Cuisine      string
+	Address      interface{}
+	Borough      string
+	Grades       interface{}
+}
+
 func main() {
 	if err := godotenv.Load(); err != nil {
 		log.Println("No .env file found")
 	}
 
 	var uri string
 	if uri = os.Getenv("MONGODB_URI"); uri == "" {
-		log.Fatal("You must set your 'MONGODB_URI' environment variable. See\n\t https://www.mongodb.com/docs/drivers/go/current/connect/mongoclient/#environment-variable")
+		log.Fatal("You must set your 'MONGODB_URI' environment variable. See\n\t https://www.mongodb.com/docs/drivers/go/current/usage-examples/#environment-variable")
 	}
 
 	client, err := mongo.Connect(options.Client().ApplyURI(uri))
@@ -33,25 +43,25 @@ func main() {
 		}
 	}()
 
-	// begin distinct
-	coll := client.Database("sample_mflix").Collection("movies")
-	filter := bson.D{{"directors", "Natalie Portman"}}
+	// Filters the collection for documents where the value of cuisine is "Tapas"
+	coll := client.Database("sample_restaurants").Collection("restaurants")
+	filter := bson.D{{"cuisine", "Tapas"}}
 
-	// Retrieves the distinct values of the "title" field in documents
+	// Retrieves the distinct values of the "borough" field in documents
 	// that match the filter
 	var arr []string
-	err = coll.Distinct(context.TODO(), "title", filter).Decode(&arr)
+	err = coll.Distinct(context.TODO(), "borough", filter).Decode(&arr)
 	if err != nil {
 		panic(err)
 	}
-	// end distinct
 
-	// Prints the distinct "title" values
+	// Prints the distinct "borough" values
 	for _, result := range arr {
 		fmt.Println(result)
 	}
 
 	// When you run this file, it should print:
-	// A Tale of Love and Darkness
-	// New York, I Love You
+	// Brooklyn
+	// Manhattan
+	// Queens
 }