如何在oracle中使用xmltable？

Question

我正在使用Oracle的XML DB来创建用户配置文件.我将用户配置文件存储在单个XMLTYPE列中,并在表中包含其他关系列(id,username,password).XML具有以下格式:

<profile>
<subject>I
       <action>like
           <object>sports</object>
               ...
           <object>music</object
       </action>
    </subject>
</profile>

我使用了以下查询,

SELECT *
FROM user,
XMLTABLE(
 '//profile'
 PASSING user.profile
 return COLUMNS action VARCHAR2(20) PATH '/subject/action',
         object VARCHAR2(30) PATH '/subject/action/object'
);

这没什么.我怎么能让这个东西工作？

Answer 1

action并且object您的示例不在同一级别,因此您的查询必须执行其他步骤.这是一个例子:

SQL> create table users (id number, profile xmltype);

Table created.

SQL> insert into users values (1, XMLTYPE('<profile>
  2      <subject>I
  3         <action>like
  4             <object>sports</object>
  5             <object>music</object>
  6         </action>
  7      </subject>
  8  </profile>'));

1 row created.

SQL> select u.id, x.action, x.object.getStringVal()
  2    from users u,
  3         XMLTABLE('/profile/subject/action'
  4                  passing u.profile
  5                  columns action VARCHAR2(30) PATH 'text()',
  6                          object XMLTYPE PATH 'object') x;

ID  ACTION  X.OBJECT.GETSTRINGVAL()
--- ------- --------------------------------------------------
1   like    <object>sports</object> <object>music</object>

正如你所看到的,我们得到了节点,而不是你想要的,所以我们添加了一个XMLTABLE:

SQL> select u.id, x.action, y.object
  2    from users u,
  3         XMLTABLE('/profile/subject/action'
  4                  passing u.profile
  5                  columns action VARCHAR2(30) PATH 'text()',
  6                          object XMLTYPE PATH 'object') x,
  7         XMLTABLE('/object'
  8                  passing x.object
  9                  columns object VARCHAR2(30) PATH '.') y;

ID  ACTION  OBJECT
--- ------- -------
1   like    sports
1   like    music