Oracle UpdateXML()更改XML结构?
问题描述:
当我打电话给UpdateXML()
时,我发现空节点正在转换为速记XML。有没有办法阻止UpdateXML()
以这种方式运行,也许是一个标志或设置或替代XPath表达式来告诉它保留原始结构?Oracle UpdateXML()更改XML结构?
/* Example 1 */
SELECT UpdateXML(xmlData, '/TEST/VALUE/text()', 'hello') as "Example 1"
FROM (SELECT XMLType('<TEST><VALUE>hi</VALUE></TEST>') as xmlData
FROM DUAL);
Example 1
---------
<TEST><VALUE>hello</VALUE></TEST>
/* Example 2 */
SELECT UpdateXML(xmlData, '/TEST/VALUE/text()', 'hello') as "Example 2"
FROM (SELECT XMLType('<TEST><VALUE></VALUE></TEST>') as xmlData
FROM DUAL);
Example 2
---------
<TEST><VALUE/></TEST>
我想看到什么:
/* Desired Output, vs. Example 2 */
SELECT UpdateXML(xmlData, '/TEST/VALUE/text()', 'hello') as "Desired Output"
FROM (SELECT XMLType('<TEST><VALUE></VALUE></TEST>') as xmlData
FROM DUAL);
Desired Output
--------------
<TEST><VALUE></VALUE></TEST>
答
我想你可以用临时值替换空的文本,更新所有其他的文本,然后用替换临时值避免问题一个null。
我不明白的XPath,有可能是一个更好的方法来做到这一点,但是这似乎工作:
SELECT
--#3: Replace the temporary value with null, this keeps the start and end tag
UpdateXML(
--#2: Replace everything but the temporary value
UpdateXML(
--#1: Replace empty text with a temporary value
UpdateXML(xmlData, '/TEST/VALUE[not(text())]', '<VALUE>TEMPORARY VALUE</VALUE>')
,'/TEST/VALUE[text()!="TEMPORARY VALUE"]/text()', 'hello')
,'/TEST/VALUE[text()="TEMPORARY VALUE"]/text()', null) examle
FROM (SELECT XMLType('<TEST><VALUE>hi</VALUE><VALUE>hola</VALUE><VALUE></VALUE></TEST>') as xmlData FROM DUAL);
有趣的方法,烨它的作品! – wweicker