Question

我有一个关于如何打印已定义类型的对象的所有值的问题。我有一个PROJECTT类型对象的表SP。当我在SP中查询其对象的行时，它返回对象的类型（PROJECTT）但不返回对象的内容。 PROJECTT类型有5个varchar列，这就是我要返回的内容。

以下是我的表格的SQL和类型

set echo on
set serveroutput on

drop table ACTIVES;
drop table POBJECT;
drop type ACTIVEST;
drop type POBJECTT;


create type POBJECTT as
   object (p# varchar(5), pname varchar(20), color varchar(10),
           weight number, city varchar(10));

create table POBJECT of POBJECTT;
   insert into POBJECT(p#, pname, color, weight, city) values
    ('P1', 'Nut', 'Red', 12, 'London');
   insert into POBJECT(p#, pname, color, weight, city) values
   ('P2', 'Bolt', 'Green', 17, 'Paris');
   insert into POBJECT(p#, pname, color, weight, city) values
   ('P3', 'Screw', 'Blue', 17, 'Rome');
   insert into POBJECT(p#, pname, color, weight, city) values
   ('P4', 'Screw', 'Red', 14, 'London');
   insert into POBJECT(p#, pname, color, weight, city) values
   ('P5', 'Cam', 'Blue', 12, 'Paris');
   insert into POBJECT(p#, pname, color, weight, city) values
   ('P6', 'Cog', 'Red', 19, 'London');

  create type ACTIVEST as table of ref POBJECTT;
   /

  create table ACTIVES(s# varchar(5), sname varchar(20), status number, 
                     city varchar(10), sp ACTIVEST)

然后使用Java SAX解析器和XML文件，我在ACTIVES的sp列中填充了对POBJECTS表中行的引用。

我正在尝试使用select语句打印这些行。我不太确定如何在SP中获取对象的值，所以我开始使用类似的东西：

select * from (select sp from actives where S# = 'S1')

Answer 1

select
    deref(column_value).p# p#
    ,deref(column_value).pname pname
    ,deref(column_value).color color
    ,deref(column_value).weight weight
    ,deref(column_value).city city
from actives cross join table(sp)
where s# = 'S1';

P#    PNAME                COLOR          WEIGHT CITY
----- -------------------- ---------- ---------- ----------
P1    Nut                  Red                12 London
P2    Bolt                 Green              17 Paris

SQL>

假设你之前运行了这样的插入：

insert into actives
select 'S1', 'sname', 0, 'city'
    ,activest(
        (select ref(p) from pobject p where p# = 'P1')
        ,(select ref(p) from pobject p where p# = 'P2')
    )
from dual;

此外，您的ACTIVES DDL对我不起作用。我必须在其末尾添加nested table sp store as sp_tab;。

从嵌套表SQL列中选择

1 个答案: