文档解释
ORA-30007: CONNECT BY ROOT operator is not supported in the START WITH or in the CONNECT BY condition
Cause: An attempt was made to use CONNECT BY ROOT operator in the START WITH or in the CONNECT BY condition.
Action: Remove CONNECT BY ROOT operator from the START WITH or from the CONNECT BY condition.
Oracle 数据库中出现 ORA-30007：CONNECT BY ROOT 操作符在 START WITH 或 CONNECT BY 条件中不受支持 的报错时，表明有在 START WITH 或 CONNECT BY 条件中应用CONNECT BY ROOT 操作符。
官方解释
由于 CONNECT BY ROOT 操作符不支持在 START WITH 条件或 CONNECT BY 条件中使用，所以可以避免此 ORA-30007 错误。
常见案例
这个错误常常发生在写入Hierarchical Queries的SQL文，特别是在写入下面的SQL语句的时：
SELECT *
FROM employee e
START WITH ROOT = ‘JOHN’
CONNECT BY PRIOR e.manager_id = e.emp_id
ORDER BY e.emp_name;
一般处理方法及步骤
如果想要避免该错误，只需要将“ROOT =”在START WITH 条件中替换为“employee_name =”或“employee_id =”就可以了。
例如：
SELECT *
FROM employees e
START WITH e.employee_name = ‘John’
CONNECT BY PRIOR e.manager_id = e.employee_id
ORDER BY e.employee_name;
