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

Another way to count last position is to slit string to array by delimeter equals to needed character and then substract length of characters for the last element from the length of whole string

CREATE FUNCTION last_pos(char, text) RETURNS INTEGER AS
$$
select length($2) - length(a.arr[array_length(a.arr,1)]) 
from (select string_to_array($2, $1) as arr) as a
$$ LANGUAGE SQL;

For the first position it is easier to use

select position('#' in '2010-####-3434');