Tutorial: Update a user’s pain level

In this tutorial, you’ll learn how to update a user’s pain level using the PATCH method to change a specific field in the user resource. Whether a user’s pain increases or decreases, keeping this information current helps them track and change their recovery approach, if necessary.

Expect this tutorial to take about 10 minutes to complete.

Before you start

Make sure you’ve completed the Getting Started guide on the development system you’ll use for the tutorial.

Update a user’s pain level

Updating a user’s pain level requires using the PATCH method to change the user resource in the service. The PATCH method allows you to update specific fields without sending the entire user object.

This example updates the pain level for a user from 7 to 4.

Make sure your local service is running, or start it by using this command in the terminal:

 cd <your-github-workspace>/SciaticaSisters-API/api
 json-server -w sciatica-sisters-db-source.json

Postman request

Open Postman and create a new request:
1. Click New > HTTP or the + icon in the header.
2. Set the request method to PATCH using the corresponding dropdown menu.
3. In the request URL field, enter:
```
{base_url}/users/1
```
Set up the request headers:
1. Click the Headers tab below the URL field.
2. Add a header:
  - Key: Content-Type
  - Value: application/json
Set up the request body:
1. Click the Body tab below the URL field.
2. Select raw from the radio button options.
3. Select JSON from the dropdown menu on the right.
4. In the text area, enter:
```
{
  "painLevel": 4
}
```
Click Send to make the request.

The system returns the complete updated user object with the new pain level. Note that only the painLevel field changed, while all other fields remained the same.

 {
   "id": 1,
   "firstName": "Sarah",
   "lastName": "Johnson",
   "email": "s.johnson@example.com",
   "age": 42,
   "painLocation": "lower-back-left",
   "painLevel": 4,
   "diagnosisDate": "2024-03-15"
 }

cURL request

Open your terminal and run this command:

curl -X PATCH {base_url}/users/1 \
  -H "Content-Type: application/json" \
  -d '{"painLevel": 4}'

The system returns the complete updated user object with the new pain level. Note that only the painLevel field changed, while all other fields remained the same.

 {
   "id": 1,
   "firstName": "Sarah",
   "lastName": "Johnson",
   "email": "s.johnson@example.com",
   "age": 42,
   "painLocation": "lower-back-left",
   "painLevel": 4,
   "diagnosisDate": "2024-03-15"
 }

Check your results

Postman verification

Create a new request in Postman.
Set the request method to GET.
In the request URL field, enter:
```
{base_url}/users/1
```
Click Send.
You should see that the painLevel is now 4 instead of the original value of 7. All other user information remains unchanged.

cURL verification

Run this command:
```
curl -X GET {base_url}/users/1
```
You should see that the painLevel is now 4 instead of the original value of 7. All other user information remains unchanged.

Common errors and troubleshooting

Pain level not updating

If the pain level doesn’t change, verify you’re using the correct field name painLevel in camelCase. Using pain_level, PainLevel, or other variations won’t work.

Invalid pain level value

The pain level must be a number between 1 and 10. Values outside this range or non-numeric values may cause errors or unexpected behavior.

404 not found error

If you receive this error, the user ID in your request URL doesn’t exist. Verify the correct user ID by calling GET on /users first to see all available users.

What you learned

After completing this tutorial, you now know how to update a specific field in a user resource using the PATCH method with Postman or cURL. This is useful when a user reports changes to their pain level without needing to update their entire profile. You’re now able to accurately track user progress.

Next steps

Log your first activity to start tracking exercises.
Compare exercises to see which activities are effective.
Create a user profile to add a patient.

Put exercise log by ID
Delete exercise log by ID

Security note

In a production environment, this operation would require proper authentication to ensure only authorized users can change patient data. See Authentication for details.