Employee        Manager            Pathlen Path --------------- --------------- ---------- ------------------------------ Gietz           Higgins                  1 /Higgins/Gietz Gietz           King                     3 /King/Kochhar/Higgins/Gietz Gietz           Kochhar                  2 /Kochhar/Higgins/Gietz Higgins         King                     2 /King/Kochhar/Higgins Higgins         Kochhar                  1 /Kochhar/HigginsThe 何用汇总following example uses a GROUP BY clause to return the total salary of each employee in department 110 and all employees below that employee in the hierarchy: 1.2.3.4.5.6.7.