Being completely new to PL/pgSQL, what is the meaning of double dollar signs in this function: CREATE OR REPLACE FUNCTION check_phone_number(text) RETURNS boolean AS $$ BEGIN IF NOT $1 ~ e'^\\+\\d...

I'm trying to declare some variables using DBeaver and keep hitting this error. Unterminated dollar-quoted string at or near "$$ DO $$ DECLARE A integer; B integer; BEGIN END$$; Any ideas? ...