XML Schema 参考手册 完整 XML Schema 参考手册 The simpleType element defines a simple type that specifies information about and constraints on the values of elements or attributes with plain text content. 父元素： Attribute, element, list, restriction, schema, union (? The symbol declaration element can appear zero or once in the simpleType element.) Attribute Description Id Optional. Specifies the unique ID of the element. Name Type name. The name must be a colon-free name (NCName) defined in the XML namespace specification. If specified, the name must be unique among all simpleType and complexType elements. Required if the simpleType element is a child of the schema element, which is not allowed at other times. Any attributes Optional. Specifies any other attributes with the non-schema namespace. This example declares that the “age” element is a simple type with constraints. The value of age cannot be less than 0 or greater than 100: XML Schema 参考手册 完整 XML Schema 参考手册
In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress. Definition and usage ¶
Element information ¶
Grammar ¶
Example 1 ¶
<xs:element name="age">
<xs:simpleType>
<xs:restriction base="xs:integer">
<xs:minInclusive value="0"/>
<xs:maxInclusive value="100"/>
xs:restriction>
xs:simpleType>
xs:element>
Principles, Technologies, and Methods of Geographic Information Systems
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