Hi, ORA-01436 occurs when a row is an descendant of itself (which is what "loop" means in this context). Usually, this means a mistake in your data. It is possible to have loops in your data, but to do a hierarchical query on a subset of the data, as long as that subset does not contain any loops. If this is the case, reply with details of what your data is, exactly what you are trying to do, and the code that is producing the error.

Hi, ORA-01436 occurs when a row is an descendant of itself (which is what "loop" means in this context). Usually, this means a mistake in your data. It is possible to have loops in your data, but to do a hierarchical query on a subset of the data, as long as that subset does not contain any loops. If this is the case, reply with details of what your data is, exactly what you are trying to do, and the code that is producing the error.