Function to escape special characters in a pattern in Postgres. This is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it

regexp_quote.sql

CREATE OR REPLACE FUNCTION public.regexp_quote(IN TEXT)
    RETURNS TEXT
    LANGUAGE plpgsql
    STABLE
AS $$
    /*******************************************************************************
    * Function Name: regexp_quote
    * In-coming Param:
    *   The string to decoded and convert into a set of text arrays.
    * Returns:
    *   This function produces a TEXT that can be used as a regular expression
    *   pattern that would match the input as if it were a literal pattern.
    * Description:
    *   Takes in a TEXT in and escapes all of the necessary characters so that
    *   the output can be used as a regular expression to match the input as if
    *   it were a literal pattern.
    * Source: https://cwestblog.com/2012/07/10/postgresql-escape-regular-expressions/ * 
    *     The original one doesn't work anymore.
    ******************************************************************************/
BEGIN
    RETURN REGEXP_REPLACE($1, '([\.\+\*\?\^\$\(\)\[\]\{\}\|\\])', '\\\1', 'g');
END;
$$