Variable being lost after CONNECT BY...PRIOR query

Question

Im having an issue with the following code (snippet posted):
SELECT ewpm_project_id INTO pro_id FROM ewpm_work_package WHERE
ewpm_work_package_id = wp_id;
--can return pro_id here
SELECT ewpm_work_package_prefix, LEVEL INTO parent_prefix,
parent_level
FROM ewpm_work_package
WHERE ewpm_project_id = temp_pro_id
AND ewpm_work_package_id = wp_id
START WITH ewpm_work_package_id = pack_id
CONNECT BY PRIOR ewpm_work_package_id = ewpm_work_package_parent_id;
RETURN pro_id;
The pro_id value is correctly set during the first select statement, I
can return the pro_id in the commented position. However, I can not
return the value after the second select statement. All I am getting
back is a null value. If I remove the START WITH.. CONNECT BY
clauses in the second query, the pro_id value is returned correcly.
Has anyone experienced this before, or know what could be causing it?

Answer 1

However, I can not
return the value after the second select statement. All I am getting
back is a null value. If I remove the START WITH.. CONNECT BY
clauses in the second query, the pro_id value is returned correcly.How do you use this function ? If you use it in SQL query then any
SQL statement raising NO_DATA_FOUND exception leads to NULL returning
as a result (like the subquery in a selection list which returns no one row):
SQL> create function get_number
  2  return number
  3  is
  4   ret_val number;
  5  begin
  6  
  7   select 1 into ret_val from dual;
  8   return ret_val;
  9  end;
10  /
Function created.
SQL> select get_number from dual;
GET_NUMBER
         1
SQL> create or replace function get_number
  2  return number
  3  is
  4   ret_val number;
  5   p number;
  6  begin
  7  
  8   select 1 into ret_val from dual;
  9 
10   --This statement raises NO_DATA_FOUND
11   select 1 into p from dual where rownum = 0;
12 
13   return ret_val;
14  end;
15  /
Function created.
SQL> select get_number from dual;
GET_NUMBER
----------Check does
SELECT ewpm_work_package_prefix, LEVEL
FROM ewpm_work_package
WHERE ewpm_project_id = temp_pro_id
AND ewpm_work_package_id = wp_id
START WITH ewpm_work_package_id = pack_id
CONNECT BY PRIOR ewpm_work_package_id = ewpm_work_package_parent_id
query return anything ?
Rgds.