Regular Expression Matches in PostgreSQL

Tobias McNulty now has two problems:

regexp_matches() and regexp_match() are two similar string functions that support regular expression matching directly in the PostgreSQL database. regexp_matches() was added in PostgreSQL 8.3, and regexp_match() was added in PostgreSQL 10 (keep reading to see how ChatGPT struggled to answer this question).

Read on for that as well as plenty more information on how the two work, and even a bonus snippet on another regular expression function.