Simple Oracle stored procedure

CREATE OR REPLACE PROCEDURE P_SUMMARY_WSP IS
 
cursor csr_hierarchy IS
SELECT
  parent,
  child
FROM
  hierarchy_deep
ORDER BY
  parent;
 
answered_no_total number;
rec_csr_hierarchy csr_hierarchy%rowtype;
 
BEGIN
  -- ** preparations
  execute immediate 'truncate table l_summary_wsp';
 
  -- iterate cursor
  open csr_hierarchy;
  loop
    fetch csr_hierarchy INTO rec_csr_hierarchy;
    exit when csr_hierarchy%notfound;
 
    -- check if we already have an entry for the current person and add
    -- to that, create otherwise
    begin
      SELECT 
        answered_no INTO answered_no_total
      FROM
        pp_summary_wsp
      WHERE
        person_id = rec_csr_hierarchy.parent;
 
      -- check for current subordinate if answered no
 
      UPDATE
        pp_summary_wsp
      SET
        answered_no = answered_no_total + 1
      WHERE
        person_id = rec_csr_hierarchy.parent;
 
    exception
      when NO_DATA_FOUND then
      INSERT INTO 
        pp_summary_wsp
        (person_id, answered_no)
      VALUES
        (rec_csr_hierarchy.parent, 1);
    end;
  end loop;
 
  -- close cursor
  IF csr_hierarchy%ISOPEN then
  close csr_hierarchy;
  end IF;
 
END P_SUMMARY_WSP;