Understanding multiple conditions in connect by prior clause Oracle

Question

Hi ,
Can some one please explain me how to comprehend/understand  multiple conditions in connect by prior conditions with some example data.
I am creating a table like this
CREATE TABLE FAMiLY_TREE
GRAND_FATHERID number,
FATHER_ID number,
SON_ID number,
person_name varchar(20)
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(NULL, NULL , 5 , 'Mr X ' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(null, 5 , 6 , 'Dave' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(5, 6 , 7 , 'Vinny' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(5, 6 , 16 , 'Omy' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(5, 6 , 17 , 'Vijjy' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(6, 7 , 8 , 'Vicky' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(6, 7 , 9 , 'Varis' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(7, 8 , 10 , 'Vshnu' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(7, 8 , 11 , 'dyna' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(8, 10 , 14 , 'Marry' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(8, 10 , 15 , 'Mac' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(7, 9 , 12 , 'Garry' );
INSERT INTO  FAMILY_TREE (GRAND_FATHERID ,FATHER_ID , SON_ID , PERSON_NAME ) VALUES
(7, 9 , 13 , 'Ganny' );
SELECT
LPAD(' ', LEVEL*3) || PERSON_NAME FROM FAMILY_TREE
START WITH SON_ID= 6
CONNECT BY PRIOR SON_ID = FATHER_ID
AND PRIOR FATHER_ID = GRAND_FATHERID ;
SELECT
LPAD(' ', LEVEL*3) || PERSON_NAME FROM FAMILY_TREE
START WITH SON_ID= 6
CONNECT BY PRIOR SON_ID = FATHER_ID ;
Both These query return the same o/p
   Dave
      Vinny
         Vicky
            Vshnu
               Marry
               Mac
            dyna
         Varis
            Garry
            Ganny
      Omy
      Vijjy
Can some one please explain me comprehension of both these query or give me a example where i can understand multiple connect by prior conditions
Thanks

Answer 1

Maybe (something to play with)
with
family_tree as
(select 'Green' family,null ancestor,1 person,'Mr X' person_name,1900 born from dual union all
select 'Green',1,2,'Dave',1920 from dual union all
select 'Green',2,3,'Vinny',1940 from dual union all
select 'Green',2,4,'Omy',1945 from dual union all
select 'Green',2,5,'Vijjy',1950 from dual union all
select 'Green',3,6,'Vicky',1960 from dual union all
select 'Green',3,7,'Varis',1965 from dual union all
select 'Green',6,8,'Vshnu',1980 from dual union all
select 'Green',6,9,'Dyna',1985 from dual union all
select 'Green',8,10,'Mary',2000 from dual union all
select 'Green',8,11,'Mac',2005 from dual union all
select 'Green',7,12,'Garry',1985 from dual union all
select 'Green',7,13,'Ganny',1990 from dual union all
select 'Brown',null,14,'Joe',1950 from dual union all
select 'Brown',14,15,'Jim',1970 from dual union all
select 'Brown',14,16,'Joy',1975 from dual union all
select 'Brown',14,17,'Jay',1980 from dual union all
select 'Brown',16,18,'Jack',1995 from dual union all
select 'Brown',18,19,'Jake',2010 from dual union all
select 'Brown',18,20,'Jess',2012 from dual
select family,
       root_name||' ('||to_char(root_born)||')' "(FA/MO)THER",
       children
  from (select family,
               root_born,
               root_name,
               ltrim(sys_connect_by_path(person_name||' ('||to_char(born)||')',', '),', ') children
          from (select family,
                       connect_by_root(person_name) root_name,
                       connect_by_root(born) root_born,
                       person_name,
                       born,
                       row_number() over (partition by family,connect_by_root(person_name) order by born) rn
                  from family_tree
                 where level = 2
                connect by prior person = ancestor
         where connect_by_isleaf = 1
         start with rn = 1
        connect by prior root_name = root_name
               and prior family = family
               and prior rn + 1 = rn
order by family desc,root_born
Regards
Etbin