Step 15 of 18 of the SQL tutorial. Both kinds of IR band live in ir_peaks, told apart by source: reported is the supplier's own list, picked was found by ml-gsd when this database was built. SUM(source = 'reported') counts them per spectrum, because a true test is 1 and a false one is 0 — a conditional count with no CASE. Of the 171 spectra, 170 carry both. The Mango side finds the one that does not: $allMatch asks whether every peak is picked, and Nerol is the only answer.
It opens on the query SELECT c.preferred_name, SUM(p.source = 'reported') AS reported, SUM(p.source = 'picked') AS picked FROM ir_spectra s JOIN ir_peaks p ON p.ir_spectrum_id = s.id JOIN compounds c ON c.id = s.compound_id GROUP BY s.id ORDER BY reported DESC LIMIT 15, which you can run and change in place.
Ask the same question of a chemical dataset in SQL and in Mango and compare the two answers. The database is a SQLite file your browser downloads once and queries locally, so nothing you write ever leaves your machine — which is also why the tool needs JavaScript.