Split comma separated string using function in PostgreSQL

-- FUNCTION: public.splitstring(text, character)
-- DROP FUNCTION public.splitstring(text, character);

CREATE OR REPLACE FUNCTION public.splitstring(p_input Text, p_character Character)

RETURNS TABLE(item Text) 
LANGUAGE 'plpgsql'

COST 100
VOLATILE 
ROWS 1000
    
AS $BODY$
BEGIN 
  DECLARE v_StartIndex integer := 1; v_EndIndex integer := 0;
  BEGIN  
          IF (SUBSTRING(p_Input, length(p_Input) - 1, length(p_Input)) <> p_Character)
          THEN
                        p_Input := concat(p_Input,'',p_Character);
          END IF;

          WHILE (POSITION(p_Character IN  p_Input) > 0)
          LOOP
                v_EndIndex := POSITION(p_Character IN  p_Input);
                BEGIN
                        RETURN QUERY
                        SELECT SUBSTRING(p_Input, v_StartIndex, v_EndIndex - 1);
                END;
                p_Input := SUBSTRING(p_Input, v_EndIndex + 1, length(p_Input));
          END LOOP;
  END;    
END;
$BODY$;

ALTER FUNCTION public.splitstring(Text, Character)
OWNER TO postgres;

Result:

SELECT public.splitstring('MSSql,MySql', ',')