xml声明

• Does not alter the encoding information stored in the xml declaration of the input string that was generated by
  不会更改输入字符串的xml声明中所存储的编码信息，该字符串是由
• Specify a code page in the codepage option of the query that matches the encoding scheme that is used in the xml declaration
  在查询的codepage选项中指定与xml声明中所使用的编码方案匹配的代码页。
• The top - level item must not have any nodes other than xml declaration , dtd , element , comment , white space , or processing instruction
  顶级项不能有除xml声明、 dtd 、元素、注释、空白或处理指令之外的任何节点。
• Will store the correct encoding information - which matches the actual encoding of the string - in the encoding attribute of the xml declaration
  将在xml声明的编码属性中存储正确的编码信息（它与字符串的实际编码相匹配） 。
• The top - level item must not have any nodes other than xml declaration , document type definition , element , comment , white space , or processing instruction
  顶级项不得包含xml声明、文档类型定义( dtd ) 、元素、注释、空白或处理指令以外的任何节点。
• The xml declaration is not required , however , if used it must be the first line in the document and no other content or white space can precede it
  Xml声明不是必选项，但是如果使用xml声明，必须在文档的第一行，前面不得包含任何其他内容或空白。
• The xml declaration can contain pseudo - attributes to indicate the xml language version , the character set , and whether the document can be used as a standalone entity
  Xml声明可以包含伪属性，指示xml语言版本、字符集以及文档是否可以作为独立的实体使用。
• You are already familiar with processing instructions because most xml documents start with the xml declaration , which is itself a special processing instruction
  您已经熟悉了处理指令，因为大多数xml文档都是以xml声明开始，该声明本身就是特殊的处理指令。
• To use these extensions , developers must follow the standard xml declaration , defining namespaces with a specialized line that adds a real namespace in this example ,
  要使用这些扩展，开发人员必须遵守标准xml声明，用添加了real名称空间的专用行来定义名称空间（在本例中，