Thanks for the question regarding "connect by ", versi

March 1, 2006 - 9am Central time zone Bookmark | Bottom | Top
Reviewer: Tom Fox from Cincinnati, OH
Tom, so what I'm getting out of the above query (repeating, not repeating, whatever) is that the
START WITH clause _must_ reference the left hand side of the CONNECT BY clause. Is this correct?
--Tom
Followup March 1, 2006 - 9am Central time zone:
I don't even know what the "left hand side" of a connect by would be, so no.
start with identifies the set of ROOT NODES.
connect by builds a hierarchy of child nodes under each root.
March 1, 2006 - 9am Central time zone Bookmark | Bottom | Top
Reviewer: Tom Fox from Cincinnati, OH
Yeah, I haven't finished my coffee yet. I meant the right hand side in my post above.
--Tom
Followup March 1, 2006 - 9am Central time zone:
I don't know what the right hand side is either.
March 1, 2006 - 5pm Central time zone Bookmark | Bottom | Top
Reviewer: Tom Fox from Cincinnati, OH
Oh, you know, the right hand side.... Work with me here. :)
In this query:
scott@ORA8I.WORLD> select lpad(' ',level*2,' ')||ename ename, empno, mgr
2 from emp
3 START WITH MGR IS NULL
4 CONNECT BY PRIOR EMPNO = MGR
5 /
What I was trying to ask: Does the START WITH clause (meaning MGR on line 3) have to reference the
right side of the CONNECT BY clause (line 4, in this case), in order for the tree to be formed
correctly?
In other terms, does START WITH always have to reference one of the fields in the CONNECT BY
clause?
Followup March 2, 2006 - 9am Central time zone:
No, it does not have to.
your start with simply identifies the rows that start hierarchies.
You might want a tree for every MGR that has the JOB = 'X'
so the start with would be referencing the EMPNO column and the JOB column (to find empnos that are
mgrs and have a job = 'X' )
Can we add salary to the query? March 2, 2006 - 1pm Central time zone Bookmark | Bottom | Top
Reviewer: Mike from Dallas, TX
Hi Tom,