Case C-77/21: Judgment of the Court (First Chamber) of 20 October 2022 (request for a preliminary ruling from the Fővárosi Törvényszék — Hungary) — Digi Távközlési és Szolgáltató Kft. v Nemzeti Adatvédelmi és Információszabadság Hatóság (Reference for a preliminary ruling — Protection of individuals with regard to the processing of personal data — Regulation (EU) 2016/679 — Article 5(1)(b) and (e) — Principle of ‘purpose limitation’ — Principle of ‘storage limitation’ — Creation, from an existing database, of a database for carrying out tests and correcting errors — Further processing of data — Compatibility of further processing of those data with the purposes of the initial collection — Period of storage in the light of those purposes)