Introduction to how to open xml files

Extensible Markup Language (Extensible Markup Language, XML) is a markup language used to mark electronic documents to make them structural. It can be used to mark data and define data types , is a source language that allows users to define their own markup languages. XML is a subset of Standard Generalized Markup Language (SGML) and is well suited for Web transport. XML provides a unified method for describing and exchanging structured data independent of applications or vendors.

Format characteristics

XML is different from databases such as Access, Oracle and SQL Server. The database provides more powerful data storage and analysis capabilities, such as: data indexing, sorting, search, related consistency, etc. XML just displays data. In fact, the biggest difference between XML and other data representations is that it is extremely simple. This is a seemingly trivial advantage, but it's what makes XML unique. ​

The design difference between XML and HTML is: XML is used to store data, focusing on the data itself. HTML is used to define data, focusing on the display mode of the data.
The simplicity of XML makes it easy to read and write data in any application. This makes XML quickly become the only public language for data exchange. Although different application software also supports other data exchange formats, they will all be Supporting XML means that the program can more easily integrate with information generated under Windows, Mac OS, Linux and other platforms, and then it is easy to load XML data into the program and analyze it, and use Output results in XML format.

In order to make SGML user-friendly, XML redefines some internal values ​​and parameters of SGML and removes a large number of rarely used functions. These complex functions make SGML complicated when designing websites. XML retains the structural functions of SGML, which allows website designers to define their own document types. XML also introduces a new document type, so that developers do not need to define document types.

Simple Syntax

SGML is often used to define document type definitions (DTD) for HTML, and it is also often used to write DTDs for XML. The problem with SGML is that it allows some strange syntax, which makes creating an HTML parser a big problem:
1 Some start tags do not allow end tags, such as the tag in HTML. An error will occur if a closing tag is included.
　2 Some start tags can optionally appear with an end tag or hide the end tag
　3 Some start tags require that an end tag must appear, such as the <script> tag in HTML. <br/>　4 Tags can be nested in any order. This is allowed even if the end tags do not appear in the reverse order of the start tags, for example, This is a sample string is correct. <br/>　5 Some features require a value, such as the src feature in <img src="/static/imghwm/default1.png" data-src="picture.jpg" class="lazy" alt="Introduction to how to open xml files" >. <br/>　6 Some features do not require a value, such as the nowrap feature in . <br/>　7 It is possible to define the characteristics with or without double quotes on both sides, so <img src="/static/imghwm/default1.png" data-src="picture.jpg" class="lazy" alt="Introduction to how to open xml files" > and <img src=picture.jpg alt="Introduction to how to open xml files" > are both allowed. <br/> These problems make building a parser for the SGML language a difficult task. The difficulty in determining when to apply the above rules has caused the definition of the SGML language to remain stagnant. Taking these issues as a starting point, XML gradually enters our field of vision. <br/> XML eliminates the arbitrary syntax of SGML that previously caused headaches for many developers. In XML, the following syntax is used: <br/>　1 Any start tag must have an end tag. <br/>　2 Another simplified syntax can be used, which can express both the start and end tags in one tag. The syntax is a slash (/) immediately before the greater-than symbol, such as <tag/ >. The XML parser will translate this into <tag>. <br/>　3 Tags must be nested in the appropriate order, so the end tag must match the start tag in mirror order, for example, this is a samplestring. This is like thinking of the start and end tags as left and right brackets in mathematics: you can't close the outer brackets without closing all the inner brackets. <br/>　4 All properties must have values. <br/>　5 All attributes must be enclosed in double quotes around the value. <br/> These rules make it much easier to develop an XML parser, and they also remove the work spent in parsing SGML to determine when and where to apply those strange syntax rules. In just the first six years after XML appeared, many different languages ​​were derived, including MathML, SVG, RDF, RSS, SOAP, XSLT, and XSL-FO, while HTML was also improved into XHTML. <br/><br/>Because XML was developed by W3C, the standardization work of XML is handled by W3C’s XML working group. Members of this group are composed of experts from various places and industries. They exchange opinions on XML standards through email and propose own opinion. Because XML is a public format (it is not exclusive to any one company), you don't have to worry about XML technology becoming a profit tool for a few companies. XML is not a language that is tied to a specific browser. <br/><br/>Opening method: It can be opened with notepad, editplus and other text tool software. Multi-users save configuration files or web pages in English. Most mobile reading websites are developed based on xml. Data storage related to multi-user web page production, etc. <br/><br/>Now I will teach you how to open xml files and software. <br/><br/>Oh, actually the easiest way is to open it with an EXCEL table. . <br/><br/>You can also use Netscape 6 to open the XML document, and you can also right-click and select "View Source File" <br/>When you use Netscape 6 to open the XML document, <br/>The browser will display the root element and child elements with colored codes. <br/><br/>How to open a file in Excel <br/><br/>When you open an XML file in Excel, you will be prompted to choose one of the following methods to import XML data: As an XML list <br/>Works as read-only Book <br/>Use the XML Source task pane <br/><br/><br/>Open a file as an XML list <br/>When you open an XML source, Excel looks for XML style sheet (XSL) tags. XSL describes how data is displayed. If the corresponding tag exists, Excel prompts you to choose whether to apply the style sheet. If you choose to apply XSL, the XSL dictates how the data is displayed; in this case, the rest of the information in this section of the article no longer applies. <br/><br/>Without XSL tags, you will receive the following message: <br/><br/><br/>The specified XML source does not reference a schema. Excel creates the schema based on the XML source data. <br/>Excel will then import the data from the XML source. If the XML data contains repeated fields within an element, Excel spreads the data over multiple rows. Each row contains a unique data set. This can cause small data sets in XML to appear as many rows in Excel. <br/><br/>Open the file as a read-only workbook <br/>If you choose to open the XML source document as a read-only workbook, the first tag of the element will be used as the title and placed in cell A1. The remaining tags are sorted alphabetically and placed on the second line. When the weather report example above is opened as a read-only workbook, the data within it will be arranged into the following list of column headers: /area/city <br/>/area/country <br/>/area/region <br/> /area/state <br/>/date <br/>/measurements/h-index <br/>/measurements/humidity <br/>/measurements/skies <br/>/measurements/temperature <br/>/measurements/uv-index <br/>/measurements isibility <br/>/measurements/wind/direction <br/>/measurements/wind/windspeed <br/>/time <br/>If there is a data set, the data for each column is placed in the third row of the spreadsheet superior. If the XML data contains repeated fields within an element, Excel spreads the data over multiple rows. Each row contains a unique data set. This can cause small data sets in XML to appear as many rows in Excel. <br/><br/>Using the "XML Source" task pane <br/>The schema of the XML data file is displayed in the "XML Source" task pane. You can then drag schema elements to the worksheet to map those elements to the worksheet. <br/><br/>If you open an XML data file that does not reference a schema, Excel will infer the schema of the XML data file. </script>

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