oracle - Not sure how to write connect by clause -


i have following query find employees not managers in emp table of oracle

 select * emp e1  not exists (select null emp e2                      e2.mgr=e1.empno)

i need output using start connect clause , avoiding self join

there function, connect_by_isleaf(), indicates whether given row in hierarchical query leaf node. in emp table, employees not managers leaf nodes.

so, can use function in nested hierarchical query filter non-managers:

select empno, mgr, ename  (     select empno, mgr, ename, connect_by_isleaf cbi     emp      start mgr null      connect prior empno = mgr ) cbi = 1 /

oracle has several neat functions interrogating hierarchies. find out more.


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