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', ',')