The hierarchical query shown below, works without error when
employee and manager are not the same (the row five in the
query table employee and manager having id of 102 in the
example below). If the employee has no manager
(organization head/CEO), it has to be typically setup as a
NULL value
for the query syntax to work.
The hierarchical query shown below, works without error when
employee and manager are the same by the use of
CONNECT BY NOCYCLE PRIOR
syntax. The CONNECT_BY_ISCYCLE evalues to 1 if a cycle exists.
Note: The NOCYCLE
is reqired for using
CONNECT_BY_ISCYCLE.
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