>> I want a SQL function that will allow to make one update but with several replace on the same column. <<

UPDATE Foobar -- we have no DDL or even a table name!

SET phone_nbr

= REPLACE(

REPLACE(

REPLACE(

REPLACE(

REPLACE(

REPLACE(phone_nbr, ' ', ''),

'/', ''),

'.', ''),

'-', ''),

',', ''),

'+33', '');

SQL is a declarative language. Nesting functions inside each other can be quite fast and easy for the optimizer. If you hang out with LISP programmers, this will seem quite natural 🙂