How to find the first and last occurrences of a specific character inside a string in PostgreSQL

Question

I want to find the first and the last occurrences of a specific character inside a string. As an example, consider a string named \"2010-####-3434\", and suppose the charact

Answer 1

In the case where char = '.', an escape is needed. So the function can be written:

CREATE OR REPLACE FUNCTION last_post(text,char) 
RETURNS integer LANGUAGE SQL AS $$  
select length($1)- length(regexp_replace($1, E'.*\\' || $2,''));  
$$;