Question

我正在测试代码以查询表，将结果获取为XML，并将其转换为JSON 格式，然后将其显示在屏幕上进行测试。我的问题是，当以varchar格式显示JSON（使用GetStringVal）时它可以正常工作，但是如果结果广泛，我将其显示为Clob（使用GetClobVal）。在这种情况下，显示的字符串包括文字“＆”。什么时候应该包括双引号。

接下来，我向您展示用于将xml转换为json的函数，然后是匿名块，并在小型xml上执行了测试。

我的数据库是Oracle 12.1

感谢您有兴趣帮助我。

--Define a function with the XSLT to convert the XML to JSON
SET DEFINE OFF
  CREATE OR REPLACE 
  FUNCTION style_sheet_json 
  RETURN VARCHAR2 IS
    l_xslt VARCHAR2 ( 32000 );
  BEGIN
    l_xslt := '<?xml version="1.0" encoding="UTF-8"?>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<!--
  Copyright (c) 2006, Doeke Zanstra
  All rights reserved.

  Redistribution and use in source and binary forms, with or without modification,
  are permitted provided that the following conditions are met:

  Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer. Redistributions in binary
  form must reproduce the above copyright notice, this list of conditions and the
  following disclaimer in the documentation and/or other materials provided with
  the distribution.

  Neither the name of the dzLib nor the names of its contributors may be used to
  endorse or promote products derived from this software without specific prior
  written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
  ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
  INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  THE POSSIBILITY OF SUCH DAMAGE.
-->

  <xsl:output indent="no" omit-xml-declaration="yes" method="text" encoding="UTF-8" media-type="text/x-json"/>
  <xsl:strip-space elements="*"/>
  <!--contant-->
  <xsl:variable name="d">0123456789</xsl:variable>

  <!-- ignore document text -->
  <xsl:template match="text()[preceding-sibling::node() or following-sibling::node()]"/>

  <!-- string -->
  <xsl:template match="text()">
    <xsl:call-template name="escape-string">
      <xsl:with-param name="s" select="."/>
    </xsl:call-template>
  </xsl:template>

  <!-- Main template for escaping strings; used by above template and for object-properties
       Responsibilities: placed quotes around string, and chain up to next filter, escape-bs-string -->
  <xsl:template name="escape-string">
    <xsl:param name="s"/>
    <xsl:text>"</xsl:text>
    <xsl:call-template name="escape-bs-string">
      <xsl:with-param name="s" select="$s"/>
    </xsl:call-template>
    <xsl:text>"</xsl:text>
  </xsl:template>

  <!-- Escape the backslash (\) before everything else. -->
  <xsl:template name="escape-bs-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <xsl:when test="contains($s,''\'')">
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="concat(substring-before($s,''\''),''\\'')"/>
        </xsl:call-template>
        <xsl:call-template name="escape-bs-string">
          <xsl:with-param name="s" select="substring-after($s,''\'')"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="$s"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- Escape the double quote ("). -->
  <xsl:template name="escape-quot-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <xsl:when test="contains($s,'';'')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'';''),''&quot;'')"/>
        </xsl:call-template>
        <xsl:call-template name="escape-quot-string">
          <xsl:with-param name="s" select="substring-after($s,'';'')"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise>
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="$s"/>
        </xsl:call-template>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- Replace tab, line feed and/or carriage return by its matching escape code. Can''t escape backslash
       or double quote here, because they don''t replace characters (; becomes \t), but they prefix
       characters (\ becomes \\). Besides, backslash should be seperate anyway, because it should be
       processed first. This function can''t do that. -->
  <xsl:template name="encode-string">
    <xsl:param name="s"/>
    <xsl:choose>
      <!-- tab -->
      <xsl:when test="contains($s,'';'')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'';''),''\t'',substring-after($s,'';''))"/>
        </xsl:call-template>
      </xsl:when>
      <!-- line feed -->
      <xsl:when test="contains($s,'';'')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'';''),''\n'',substring-after($s,'';''))"/>
        </xsl:call-template>
      </xsl:when>
      <!-- carriage return -->
      <xsl:when test="contains($s,'';'')">
        <xsl:call-template name="encode-string">
          <xsl:with-param name="s" select="concat(substring-before($s,'';''),''\r'',substring-after($s,'';''))"/>
        </xsl:call-template>
      </xsl:when>
      <xsl:otherwise><xsl:value-of select="$s"/></xsl:otherwise>
    </xsl:choose>
  </xsl:template>

  <!-- number (no support for javascript mantise) -->
  <xsl:template match="text()[not(string(number())=''NaN'')]">
    <xsl:value-of select="."/>
  </xsl:template>

  <!-- boolean, case-insensitive -->
  <xsl:template match="text()[translate(.,''TRUE'',''true'')=''true'']">true</xsl:template>
  <xsl:template match="text()[translate(.,''FALSE'',''false'')=''false'']">false</xsl:template>

  <!-- item:null -->
  <xsl:template match="*[count(child::node())=0]">
    <xsl:call-template name="escape-string">
      <xsl:with-param name="s" select="local-name()"/>
    </xsl:call-template>
    <xsl:text>:null</xsl:text>
    <xsl:if test="following-sibling::*">,</xsl:if>
    <xsl:if test="not(following-sibling::*)">}</xsl:if> <!-- MBR 30.01.2010: added this line as it appeared to be missing from stylesheet -->
  </xsl:template>

  <!-- object -->
  <xsl:template match="*" name="base">
    <xsl:if test="not(preceding-sibling::*)">{</xsl:if>
    <xsl:call-template name="escape-string">
      <xsl:with-param name="s" select="name()"/>
    </xsl:call-template>
    <xsl:text>:</xsl:text>
    <xsl:apply-templates select="child::node()"/>
    <xsl:if test="following-sibling::*">,</xsl:if>
    <xsl:if test="not(following-sibling::*)">}</xsl:if>
  </xsl:template>

  <!-- array -->
  <xsl:template match="*[count(../*[name(../*)=name(.)])=count(../*) and count(../*)&gt;1]">
    <xsl:if test="not(preceding-sibling::*)">[</xsl:if>
    <xsl:choose>
      <xsl:when test="not(child::node())">
        <xsl:text>null</xsl:text>
      </xsl:when>
      <xsl:otherwise>
        <xsl:apply-templates select="child::node()"/>
      </xsl:otherwise>
    </xsl:choose>
    <xsl:if test="following-sibling::*">,</xsl:if>
    <xsl:if test="not(following-sibling::*)">]</xsl:if>
  </xsl:template>

  <!-- convert root element to an anonymous container -->
  <xsl:template match="/">
    <xsl:apply-templates select="node()"/>
  </xsl:template>

</xsl:stylesheet>';

    RETURN ( l_xslt );

  END style_sheet_json;
/


DECLARE
l_xml XMLTYPE;
l_json XMLTYPE;
BEGIN

l_xml := XMLTYPE (
'<ROWSET>
 <ROW>
  <ID>4</ID>
  <DENOPAIS>Afganistán</DENOPAIS>
 </ROW>
</ROWSET>');

--Las 2 impresiones siguientes muestran lo mismo, el xml tal cual
dbms_output.put_line ( 'Shows xml as varchar');
dbms_output.put_line ( l_xml.GetStringVal());

dbms_output.put_line ('');
dbms_output.put_line ( 'Shows xml as clob');
dbms_output.put_line ( l_xml.GetClobVal());

dbms_output.put_line ('');
dbms_output.put_line ( 'Converting xml to json format...');
l_json := l_xml.TRANSFORM ( XMLTYPE ( style_sheet_json () ) );

dbms_output.put_line ('');
dbms_output.put_line ( 'Shows json as varchar');
dbms_output.put_line ( l_json.GetStringVal());

dbms_output.put_line ('');
dbms_output.put_line ( 'Shows json as clob');
dbms_output.put_line ( l_json.GetClobVal());

end;

Answer 1

不确定为什么要这样做，并且可能有更好的方法来停止它，但是作为一种变通办法，您可以将XML序列化为CLOB变量。不太确定为什么也行...

DECLARE
l_xml XMLTYPE;
l_json XMLTYPE;
l_clob CLOB;
BEGIN
...
dbms_output.put_line ('');
dbms_output.put_line ( 'Shows json as serialiaed clob');
select xmlserialize( content l_json as clob ) into l_clob from dual;
dbms_output.put_line ( l_clob );

end;
/

其中显示

...
Converting xml to json format...

Shows json as varchar
{"ROWSET":{"ROW":{"ID":4,"DENOPAIS":"Afganistán"}}}

Shows json as clob
{&quot;ROWSET&quot;:{&quot;ROW&quot;:{&quot;ID&quot;:4,&quot;DENOPAIS&quot;:&quot;Afganistán&quot;}}}

Shows json as serialiaed clob
{"ROWSET":{"ROW":{"ID":4,"DENOPAIS":"Afganistán"}}}

Answer 2

贡献解决方案的用户表示，他在几年前对此发表了评论here。

因为TRANSFORM方法返回XMLType的实例，所以当样式表的输出方法设置为text时会有一些差异。

在这种情况下正确的行为是什么？不要使字符实体转义为明文，或者保持它们原样以使XML内容保持有效。

所引用的出版物中提到的解决方法适用于Oracle 11.2，并且似乎该行为在12c中有所改变。

即使如此，也可以使用类似的方法来获得预期的CLOB输出：

ask util generate-lwa-tokens

使用Clob以json格式可视化xml内容时出现问题

2 个答案: