I am disappointed to find that, with #SQLite, an INSERT statement with both ON CONFLICT DO NOTHING and RETURNING clauses won't return anything if there is a conflict.
I have a table that's basically just for interning frequently-used strings. It has a numeric ID column and a unique text column, and I want to get the ID for a given string, inserting if necessary.
With this RETURNING behavior, that has to be done in two steps, not one.