Генерация иерархического пути - PullRequest
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Генерация иерархического пути

1 голос
/ 21 сентября 2019

У меня есть таблица classstructure: 

create table classstructure (classstructureid number(8,0), classificationid varchar2(25), parent number(8,0));

insert into classstructure(classstructureid, classificationid, parent) values(1001, 'FLEET', null);
insert into classstructure(classstructureid, classificationid, parent) values(1002, 'LIGHTDUTYVEHICLE', 1001);
insert into classstructure(classstructureid, classificationid, parent) values(1004, 'MEDIUMDUTYVEHICLE', 1001);
insert into classstructure(classstructureid, classificationid, parent) values(1022, 'ACTIVETRANSPORTATION', null);
insert into classstructure(classstructureid, classificationid, parent) values(1023, 'FACILITYWALKWAY', 1022);
insert into classstructure(classstructureid, classificationid, parent) values(1024, 'TRAIL', 1022);
insert into classstructure(classstructureid, classificationid, parent) values(1085, 'SIDEWALK', 1022);
insert into classstructure(classstructureid, classificationid, parent) values(1091, 'SDWRAMP', 1085);
commit;

select * from classstructure;

CLASSSTRUCTUREID CLASSIFICATIONID              PARENT
---------------- ------------------------- ----------
            1001 FLEET                               
            1002 LIGHTDUTYVEHICLE                1001
            1004 MEDIUMDUTYVEHICLE               1001

            1022 ACTIVETRANSPORTATION                
            1023 FACILITYWALKWAY                 1022
            1024 TRAIL                           1022
            1085 SIDEWALK                        1022
            1091 SDWRAMP                         1085

Я хотел бы свернуть записи до иерархических путей: 

HIERARCHYPATH
---------------------------
FLEET \ LIGHTDUTYVEHICLE
FLEET \ MEDIUMDUTYVEHICLE 

ACTIVETRANSPORTATION \ FACILITYWALKWAY
ACTIVETRANSPORTATION \ TRAIL
ACTIVETRANSPORTATION \ SIDEWALK
ACTIVETRANSPORTATION \ SIDEWALK \ SDWRAMP

Как я могу это сделать?

1 Ответ

1 голос
/ 21 сентября 2019

Вы можете использовать функцию sys_connect_by_path() (с Oracle 10g Release 2): 

select ltrim(sys_connect_by_path(classificationid, ' \ '),' \ ') as hierarchypath
  from classstructure c
 where parent is not null
 start with parent is null
connect by prior classstructureid = parent;

HIERARCHYPATH
--------------------------------------
FLEET \ LIGHTDUTYVEHICLE
FLEET \ MEDIUMDUTYVEHICLE
ACTIVETRANSPORTATION \ FACILITYWALKWAY
ACTIVETRANSPORTATION \ TRAIL
ACTIVETRANSPORTATION \ SIDEWALK
ACTIVETRANSPORTATION \ SIDEWALK \ SDWRAMP
...