请问这样的查询(递归树)如何处理？

表A(多级机构表)有三个字段：

ID Parentid Name

1   0            机构A

2   1            机构B

3   2            机构C

4   3            机构D

表B(车辆表)中也有三个字段：

ID Parentid（对应表A中的ID） DESC

1   4                                        车A

2   2                                        车B

3   3                                        车C

这样，要想一次性把所有信息都查出来。比如，我现在要查出机构A的所有车辆能不能用一条语句搞定。

 



 

 

 

SQL> create table table_a ( id number,parentid number,name varchar2(10));

Table created

SQL> insert into table_a values ( 1,0,'机构A');

1 row inserted

SQL> insert into table_a values ( 2,1,'机构B');

1 row inserted

SQL> insert into table_a values ( 3,2,'机构C');

1 row inserted

SQL> insert into table_a values ( 4,3,'机构D');

1 row inserted

SQL> commit;

Commit complete

SQL>

SQL> create table table_b ( id number,parentid number,descr varchar(10));

Table created

SQL> insert into table_b values (1,4,'车A');

1 row inserted

SQL> insert into table_b values (2,2,'车B');

1 row inserted

SQL> insert into table_b values (3,3,'车C');

1 row inserted

SQL> commit;

Commit complete

SQL> select * from table_a;

        ID   PARENTID NAME

---------- ---------- ----------

         1          0 机构A

         2          1 机构B

         3          2 机构C

         4          3 机构D

SQL> select * from table_b;

        ID   PARENTID DESCR

---------- ---------- ----------

         1          4 车A

         2          2 车B

         3          3 车C

SQL> select a.name,t.descr

  2    from table_b t,

  3         (

  4          select id,lpad(name,10+level*2,' ') name

  5            from table_a

  6           start with name = '机构A'

  7          connect by prior id = parentid

  8         ) a

  9  where t.parentid = a.id

10  /

NAME                                                                             DESCR

-------------------------------------------------------------------------------- ----------

         机构B                                                                   车B

           机构C                                                                 车C

             机构D                                                               车A

SQL>

 

已利用，再次表示感谢！

SELECT V.*

  FROM V_FINALPOSITION V,

       (SELECT A.AGENCYID

          FROM T_AGENCY A

         START WITH A.AGENCYID = 0

        CONNECT BY PRIOR A.AGENCYID = A.PARENTID) T

WHERE V.PARENTAGENCYID = T.AGENCYID