select sum (维修费用) from 设备表 t1,
(
select 设备编码 from 设备表
CONNECT BY PRIOR 设备编码 = 父设备编码
START WITH 设备编码='A'
) t2
where t1.设备编码=t2.设备编码 and t2.设备编码<>'A'
(
select 设备编码 from 设备表
CONNECT BY PRIOR 设备编码 = 父设备编码
START WITH 设备编码='A'
) t2
where t1.设备编码=t2.设备编码 and t2.设备编码<>'A'
connect by prior 设备编码 = 父设备编码;
语法:
SELECT sql_expn FROM [user.]table WHERE where_condition
CONNECT BY [PRIOR] expn = [PRIOR] expn
START WITH expn = expn
ORDER BY expn
变量:
sql_expn:有效的SQL表达式
user:表的主人
table: SELECT的表
where_condition:SELECT的WHERE条件
expn:任意有效的表达式
例子:
SQL
SELECT employee_name, department_name FROM employee
CONNECT BY emp_no = PRIOR department_no
ORDER BY department_no;.