I ran into an issue earlier using the GUI editor.
After adding a table, I can go to the Pick columns button and choose the columns I want, but if I join to another table, then the Pick columns button for the first table goes missing. Screenshot is below.
I'm guessing you're not showing your entire question, but you have a summarize section.
See this: Columns selector missing
Thanks for the quick reply. Yes I am doing a summarise. Actually I had added some fields to the base table in SQL, and I wanted to use the column picker to see if they were coming through into Metabase.
But I see now that when I click '+' to add a grouping, the new fields show up in the list, cool.
Once again, a well thought out product thanks,