How do I exclude NULL values in a subquery? (BigQuery - SQL - GA4)

Question

Here is my query so far:

SELECT 
  event_date, 
  event_timestamp, 
  user_pseudo_id, 
  geo.country, 
  geo.region, 
  geo.city, 
  geo.sub_continent,
  (
    SELECT
      value.string_value
    FROM
      UNNEST(event_params)
    WHERE
      key = "search_term") AS search_term,
FROM `GoogleAnlyticsDatabase`

I am trying to exclude all NULL values in the 'search_term' column.

I am struggling to identify where I need to include IS NOT NULL in my code.

Everything I have tried so far has thrown up errors.

Does anyone have any ideas?

Answer 1

Is this query giving you the expected result besides the NULL problem?

If yes, you can just wrap your query to an CTE aand filter this CTE

like

WITH

SRC AS (
SELECT 
  event_date, 
  event_timestamp, 
  user_pseudo_id, 
  geo.country, 
  geo.region, 
  geo.city, 
  geo.sub_continent,
  (
    SELECT
      value.string_value
    FROM
      UNNEST(event_params)
    WHERE
      key = "search_term") AS search_term
FROM `GoogleAnlyticsDatabase`
)

SELECT * FROM SRC WHERE search_term IS NOT NULL