`UPDATE ... FROM ( SELECT ... )` results in the error: `Update with joins not supported`

[anonimitoraf]

What happened?

This query runs fine in actual BigQuery, but results in an error failed to analyze: INVALID_ARGUMENT: Update with joins not supported in the emulator:

UPDATE `my_table`
SET description = 'new'
FROM (SELECT 'record1' as xId) AS xs
WHERE id = xs.xId;

What did you expect to happen?

I expected the query to not result in an error. Instead it should update record1

How can we reproduce it (as minimally and precisely as possible)?

• Create a table my_table with description and id columns (both strings)
• Run the query:

  UPDATE `my_table`
  SET description = 'new'
  FROM (SELECT 'record1' as xId) AS xs
  WHERE id = xs.xId;

Anything else we need to know?

I searched around for the exact error message both in this repo and https://github.com/goccy/go-zetasqlite but was unable to find anything. Why is this?

I also had a look at the supported functionality list but was unable to find anything on this.