simple fhir example

docs/working_with_fhir/working_with_fhir.md

@@ -2,5 +2,48 @@
 
 FHIR describes both a REST API based on common requests/queries and more than 130 data structures. There are many resources for learning FHIR, and the basics are covered elsewhere. A hosted demo system can be used to increase your understanding of FHIR basics. Some great resources are:
 
-* The [HAPI FHIR Test Server](http://hapi.fhir.org/) The test server has a great web interface so you don't need to dig into a terminal to issues commmands.
-* SmileCDR's [Intro to FHIR](https://www.youtube.com/watch?v=YbQcJj1GqH0&t=2175s). This is a video that explains the why and how of FHIR.
+* The [HAPI FHIR Test Server](http://hapi.fhir.org/) The test server has a great web interface so you don't need to dig into a terminal to issues commmands. This is a great way to understand the REST API and the diverse types of resources.
+* SmileCDR's [Intro to FHIR](https://www.youtube.com/watch?v=YbQcJj1GqH0&t=2175s). This is a video that explains the why and how of FHIR.
+
+## Simple FHIR example
+
+As a simple introduction, consider the following snippet. Here are the key takeaways:
+
+* Its `resourceType` is bundle, meaning it can contain multiple resources, and of different types. This bundle is of type collection, meaning it just for reference.
+* It has two entries, meaning individual resources, both of `resourceType` is location.
+* The bundle has an `id`, but so does each location resource.
+* `resource.partOf` links the two resources. Location/3 is part of Location/2. This is important. It nests the resources.
+
+```json
+{
+  "resourceType": "Bundle",
+  "id": "3ad0687e-f477-468c-afd5-fcc2bf897819",
+  "type": "collection",
+  "entry": [
+    {
+      "fullUrl": "http://hl7.org/fhir/Location/2",
+      "resource": {
+        "resourceType": "Location",
+        "id": "2",
+        "status": "active",
+        "name": "USSS Enterprise-D",
+        "mode": "instance"
+      }
+    },
+    {
+      "fullUrl": "http://hl7.org/fhir/Location/3",
+      "resource": {
+        "resourceType": "Location",
+        "id": "3",
+        "status": "active",
+        "name": "USSS Enterprise-D Sickbay",
+        "mode": "instance",
+        "partOf": {
+          "reference": "Location/2",
+          "display": "USS Enterprise"
+        }
+      }
+    }
+  ]
+}
+```