Learn Oracle SQL : The Hierarchical Query Clause

Learn Oracle SQL : The Hierarchical Query Clause: In this video, I show you how to use the Hierarchical Query Clause in Oracle SQL to build a basic hierarchical query.

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[JoseAlvarez-dlhm]

Awesome, I finally got what is the use for hierarchical queries, thanks a lot.

[AwarapanBihu]

Simple and straight to the core. Incredible job !

[backyardwilderness]

Thank you for such a simple method of explaining the concepts.. Thanks again!

[adarshsrivastava]

Literally superb man..hats off to u .You just cleared by all doubt which I had before watching this video...You explained it as simple as it could be explain...waiting for the other tutorials of Hierarchical queries...Good job bro...keep doing this

[sravannayini]

Thanks for explaining.Its super simple.Please make more videos.

[phuongnamnguyen]

Can you help me with sql server
I want to result like there
Top level. Under level1
Top level. Under level 2
Top level. ....

[kevinsantana]

nice example, making something complex simple

[kirankumar-jwxi]

Could you please tell us the answer for the above question

[ChatkareChapri]

Please help me to solve below query .
I used is to find duplicates .

This is working fine

SELECT distinct a.*
FROM   HR.emp1 a
where exists(select count(*) from
  (SELECT b.* FROM HR.emp1 b WHERE b.rowid = a.rowid
    INTERSECT
    SELECT c.* FROM HR.emp1 c WHERE c.rowid <> a.rowid
));


But when I used it inside below query it is not identifying the rowid, I tried it by using alais too but without success .

SELECT distinct a.*
FROM   HR.emp1 a
where 1 = (select count(*) from (select count(*) from
  (SELECT b.* FROM HR.emp1 b WHERE b.rowid = a.rowid
    INTERSECT
    SELECT c.* FROM HR.emp1 c WHERE c.rowid <> a.rowid
)));

Please help me to resolve the query