Operations on tree nodes

Question

Hi everyone, it's me again, with another issue =)
I need to be able to rename all node under a specific node in a hierarchy. Let's take this table and the following sample data.
CREATE TABLE organisations
  organ_id NUMBER(10) PRIMARY KEY,
  parent_id NUMBER(10),
  NAME VARCHAR2(255),
  CONSTRAINT fk_org_to_parent_org
     FOREIGN KEY(parent_id) REFERENCES organisations(organ_id)
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (1,null,'Organisation 1');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (2,null,'Organisation 2');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (21,2,'Organisation 21');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (22,2,'Organisation 22');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (221,22,'Organisation 221');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (2211,221,'Organisation 2211');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (3,null,'Organisation 3');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (31,3,'Organisation 31');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (311,31,'Organisation 311');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (3111,311,'Organisation 3111');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (32,3,'Organisation 32');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (321,32,'Organisatin 321');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (3211,321,'Organisation 3211');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (3212,321,'Organisation 3212');
Insert into ORGANISATIONS (ORGAN_ID,PARENT_ID,NAME) values (313212,3212,'Organisation with an id containing 31.');I'd like to rename some nodes in the tree. For example, how can I for example add the '- renamed' to all nodes under the node with organ id = 31?
I tried the following but it's not good because whenever I have another ID containing the number 31, I have a wrong result.
SELECT organ_id, lpad(' ', LEVEL * 2) || name,
       -- sys_connect_by_path(organ_id, ','),
        case when instr( sys_connect_by_path(organ_id, ','), '31') > 0 then
           name || '- renamed'
           else
           name
        end
  FROM organisations
START WITH parent_id is null
CONNECT BY PRIOR organ_id = parent_id;The following query does the job:
select organ_id, lpad(' ', level * 2) || name,
       -- sys_connect_by_path(organ_id, ','),
        case when organ_id IN (SELECT organ_id
                                 from organisations
                                start with organ_id = 31
                              CONNECT BY prior organ_id =  parent_id) then
              name || '- renamed'
           else
           name
        end
  from organisations
start with parent_id is null
CONNECT BY PRIOR organ_id = parent_id;I wanted to know if it was possible without the sub select?
Thanks

Answer 1

Hi,
user13117585 wrote:
... In this case, I want to add something in the end of the name of both organisations (31 & 221)221) and all their children nodes.It will be worth your time to learn and use the right terms. If you don't, you'll waste a lot of time (both yours and that of the people trying to help you) by getting answers to what you said, rather than what you wanted.
"Child" means an node exactly one level down the hierarchy, a "descendant" means a node any number of levels down.
In your sample data, 311 is a child of 31, and 311 is also a descendant of 31. (Children are always descendants.)
3111 is not a child of 31, but 3111 is a descendant of 31. (Descendants are not always children.)
If you want to mark all the descendants of organ_ids found in table t:
SELECT  o.organ_id
,     LPAD (' ', LEVEL * 2) || o.name          AS name
,     CASE
         WHEN  INSTR ( SYS_CONNECT_BY_PATH ( NVL2 ( t.organ_id
                                   , '+'
               ) > 0
         THEN  name || '- renamed'
            ELSE  name
        END                         AS name_r
FROM      organisations     o
LEFT OUTER JOIN          t  ON     o.organ_id     = t.organ_id
START WITH     o.parent_id       IS NULL
CONNECT BY      PRIOR o.organ_id  = o.parent_id;As you were doing before, display SYS_CONNECT_BY_PATH to see what it's doing. You'll see, that, instead of producing a string like
',3,31,311', which contains information that can lead you to what you need to know, the query above produces a sting like
',+,-,+', which contains exactly what you need to know.