Hasnain says:

This is pretty cool. I’ve been doing a lot of SQL lately and developer efficiency is a mess (I have a lot to learn).

“In the query on the right, the author is trying to combine timestamps in milliseconds from the table user_login_events_mobile with timestamps in nanoseconds from the table user_login_events_desktop — an understandable mistake, as the two columns have the same name. But because the tables’ schema have been annotated with user-defined types, UPM’s typechecker catches the error before the query reaches the query engine; it then notifies the author in their code editor. Without this check, the query would have completed successfully, and the author might not have noticed the mistake until much later.”

Posted on 2022-11-30T19:22:49+0000