Sql 树结构查询 Fetch

Question

I want to see my structure is such as below:

Parent_1 (Lvl1)
>>Version_1(Lvl2)(first child of Parent_1)
>>> Version_1_1(Lvl3)
>>>> Version_1_1_1(Lvl4)
>>>> Version_1_1_2(Lvl4)
>>>Version_1_2(Lvl3)
>>>Version_1_3(Lvl3)
>>>>Version_1_3_1(Lvl4)
>>>>Version_1_3_2(Lvl4)
>>>>>Version_1_3_2_1(Lvl5)
>>Version_2(Lvl2) (second child of Parent_1)

Parent_2 (Lvl1)
>>Version_3(Lvl2)(only child of Parent 2)

I want my data to be visible like this tree structure. Sort my Parent level asc , next child of the first parent and further down like a tree.

Data is split in 3 tables

1. ParentTable -Id of parent and description
2. Version Table- Version ID(Vesrion_1, Version_2) and Version Description(Desc for version) and Main Parent it belongs to (Parent_! or Parent_2) and also its immediate parent(For Version Id Version_1_1_1 Immediate Parent will be stored as Version_1_1) and also the level (Version_1_1 is at level3)
3. Activity Table- Active version of the versions for all the parents. - Version ID(Vesrion_1, Version_2) and also its immediate parent(For Version Id Version_1_1_1 Immediate Parent will be stored as Version_1_1) and also the level (Version_1_1 is at level3)

How can i achieve the above structure. I wil have version upto 5 levels for each parent. I want the view to user be in the above structure with all the data i have in format mentioned above

Thanks in advance

Answer 1

You may want to look at the "connect by prior" in SQL. Yet I warn you about the performance issue, you might prefer to use a string to rank your results and query it.

root : 0000

L1 : 1000

L2 : 2000

L1-1 : 1100 ...

then you can order by tree_code and filter with like("11%")

Pour info la syntaxe de mise en œuvre des requêtes hiérarchiques est :

SELECT * FROM NOM_TABLE
CONNECT BY [NOCYCLE]
[PRIOR] colonne01 = [PRIOR] colonne02 [AND ...]
[START WITH condition] ;