How Create User ID for GA4 to BigQuery

Question

Purpose

I want to create user_id in GA4 which was linked to BigQuery.

What I've tried

I followed this document:

1. GTM to manage GA4.

2. GA4 links to BigQuery.

   (Now I got data from my website, and data can collect in BigQuery.)

3. Passed user_id to dataLayer:

   • I've added the following script in HEADER which above gtm.js.

   • I'm not sure whether using a string (USER_ID) as input at this step will affect the result or not.

   <script>
      dataLayer.push({
        'user_id': 'USER_ID'
      });
   </script>
   

4. Create variable of dataLayer:

   

5. Adjust GTM code:

   

Expected & Results

• I expected that I build comparision like:

  

  However, I cannot do that:

  

• I expected my BigQuery can get a new column user_id (no happen)

Questions

• Did I mess up something in the process?
• Could the user_id passed from the front-end and back-end be passed to BigQuery as I expected?

Answer 1

From your process 5

The key should be user_id Not userId. It's different for GA4.

Follow the document