frank oo java

原始表:
CREATE TABLE departments (deptid INT,
            deptname VARCHAR(20),
            empcount INT,
            superdept INT)

查询某个部门的所有子部门的总人数
Oracle:

SELECT sum(empcount) FROM STRUCREL
            CONNECT BY PRIOR superdept = deptid
            START WITH deptname = '部门名称';

DB2:

WITH temptab(deptid, empcount, superdept) AS
            (    SELECT root.deptid, root.empcount, root.superdept
            FROM departments root
            WHERE deptname='Production'
            UNION ALL
            SELECT sub.deptid, sub.empcount, sub.superdept
            FROM departments sub, temptab super
            WHERE sub.superdept = super.deptid
            )
            SELECT sum(empcount) FROM temptab