Then change your function to operate across the dataframe and return a different dataframe?

You can add multiple columns at the same time or do a merge statement of some kind

Why do you want to use a web sql interface? Imo even the fancy proprietary offerings of companies like snowflake and databricks aren’t that great.

Better to use a regular database query tool like dbeaver https://dbeaver.io or datagrip https://www.jetbrains.com/datagrip/

But you can run PostgreSQL in docker https://hub.docker.com/_/postgres/. Looks like there’s a web ui tool also but never used it https://postgresqlstudio.org