Reply To: Understanding SQL Server parsing of GA4 BigQuery RECORD columns

[Oliver]

Alright! You can use the UNNEST function in BigQuery, which allows you to flatten array data into a table. Here’s an example using the ‘event_params’:

`
SELECT
EP.key AS event_param_key,
COUNT(*) AS occurrences
FROM
— Replace the table name with your table
bigquery-public-data.ga4_obfuscated_sample_ecommerce.events_*,
UNNEST(event_params) AS EP
WHERE
— Replace with your date range
_TABLE_SUFFIX BETWEEN ‘20201201’ AND ‘20201202’
GROUP BY
event_param_key
ORDER BY
event_param_key ASC;
`

In this SQL query, each record in the ‘event_params’ array is transformed into a row in the ‘EP’ table, which you can then query as usual.

For more details, have a look at [this article](https://medium.com/firebase-developers/using-the-unnest-function-in-bigquery-to-analyze-event-parameters-in-analytics-fb828f890b42) which explains how to use the UNNEST function in depth when analyzing event parameters in Analytics.