XML SCHEMA full contact

XML SCHEMA full contact

Time: 2001/05/13 19:21 Author: onecenter Chinese XML Union

On May 2, 2001, after more than three years, XML's Schema finally became a fruit. In this way, XML, XML Schema and Namespace have become a formal standard for W3C. This is a historic moment worth celebrating, meaning XML syntax specification has laid a solid foundation. China XML Alliance introduces you the latest XML Schema standard and its application in MSXML 4.0.

XML Definition Language: DTD, XDR and XSD XML Schema's Sepament Use XSD Verify XML XML Schema and Name XML Definition Language: DTD, XDR and XSD We know that XML documents are formatted in format and have two constraints. The format is well suited for all XML documents, that is, to meet the provisions of the format in the XML standard. The XML document is called a valid XML document when the XML document satisfies certain semantic constraints. Currently used XML definition languages ​​have DTD, XDR, and XSD. The Document Type Definition (DTD) Document Type Defines the content mode of the various elements in the XML document with independent grammar different from XML. This language directly follows the method of defining the SGML language. DTD allows the XML document to maintain consistent DTD to share DTD provides the formation and complete definition of XML communication. Each XML document has a single DTD to limit SCHEMA-like DTD, and Schema can specify a structure or model of a particular document. Using the SCHEMA language to describe the following benefits: SCHEMA uses XML syntax SCHEMA can use XML parsers to parse SCHEMA allows global elements (in the same way in the entire XML document) and local elements (Elements) There are different meanings in a particular context) SCHEMA provides a wealth of data types (such as integer, Boolean, date type, etc.); and the data type in an element can be regulated, and can even customize data type XDR xdr as needed. The full name is XML-Data Reduced Language, which is a branch that defines the XML language that is derived by the draft of XML-DATA. Since Microsoft proposes XML-DATA, and XDR is also widely used in its software after the application is revised. The products currently support XDR Schema include: Microsoft BizTalk Server Microsoft SQL Server 2000 Microsoft Office 2000 Microsoft IE5.0 and subsequent version XDR also gave support for ExtensIlity XML Authority Editing tools. XSD Schema's most formal XML Schema language is the XML Schema specification specified by W3C, referred to as XSD (XML Schema Definition). XSD also provides a method of support and structural definitions of data types. On May 2, 2001, the XML Schema specification became the formal recommendation standard for W3C. This means that after more than three years of development, XML's Schema standard finally repaired. In this way, XML, XML Schema and Namespace have become the formal of W3C. This is a historic moment worth celebrating, meaning the XML syntax specification has laid a solid foundation. The extensive development and application of XML will become a reality. Below we will focus on the latest XML Schema standard.

XML Schema's full picture

We use the actual example to introduce XML Schema's usage. For example, there is such an XML instance document: to Zunbao Male 001 1576-3-2 Baijingjing Female 002 1578-4-25 This document is defined by DTD as follows: But the data type of the text elements such as Name and Genda, SID is a unified character type, and in fact, we generally require a more stringent restrictions on them. For example, ask NAME to still be a character type, while genda is an optional enumeration type, can only take a male or female, SID requirement is a three-digit integer type, and requires Birthday to date. Name and birthday definitions are relatively simple: Where string and Date type are the basic data types from SCHEMA (Primary Data Type). Minoccurs and maxoccurs are at least maximum number of times, which is indicated and only once. This is the easiest element declaration. Two data types are available in XML Schema: One is the basic data type we just contact or is called built-in data type; another is the extension data type, which is both the user's own scaled data type on the basis of the basic data type. There is no specified gender type in Schema, nor directly specifying the data type of three integers, but gender is an enumeration type of male and two choices; each of the SID is non-negative, so we can define two Class extension data types, then restrict GENDA and SID elements.

has the element of the most basic four text content, how to define the STUDENT element of its parent element? Since the Student element is composed of sub-elements, it is called its bit complex type element in Schema.

Moreover, its sub-elements are sequences of sequence, so this declaration Student element: additional studentlst elements contains the Student element, and The way is one or more, or may not appear, the way in Schema can be expressed by mioccurs and maxoccurs: Finally we will include these elements and data types of statements in the Schema root element Medium:

Use XSD check XML by XML Schema, you can use to verify the semantics and structure of the XML document. The MSXML 4.0 technology preview version has provided features with XSD Schema to verify the XML document. When you check the document, add Schema to the XMLschemacche object, set its object, SET The Schemas Property of A DomDocument object's Schemas property references to Schema in the XMLscheMacche object. The check operation is automatically performed when the XML document is loaded into the DomDocument object. We may use examples to explain how to implement an XML document check by programming in Visual Basic. These include: Books.xsd Schema books.xml used to verify the books.xml file will be loaded and the Books.xsd controls the Visual Basic check code to create an XMLSChemacache object, add Schema to it, then Set the Shemas property of the Schemas Property of the Domdocument object. In the beginning, you have to do the following: Open Visual Basic 6.0, select the Standard Exe New project Select References in the Project menu. Select Microsoft XML in the Available References list, V4.0 Add a Command button to Form1 to store the item books XML enters the following XML code in the XML editor or even a normal text editor, and stores Books.xml: Gambardella, matthew