How to use regular expression in SQL query?

Question

MySQL

Hello. There is a request

UPDATE ИМЯ_ТАБЛИЦЫ SET ИМЯ_ПОЛЯ = REPLACE(ИМЯ_ПОЛЯ, 'строка для замены', 'чем заменяем');

It is necessary that under the "string to replace" such values ​​would fall into
the text I want#this-that-text-remove The
request should remove
#this-that-text-remove
and leave
the text I want.
Remove everything after the "#", along with the hash.
In general, I don’t understand anything about muscle. Tell me please.