XML Schema and their Attributes
An XML Schema defines the elements, child elements and the attributes that can appear in a document. It can also define the order, the number of child elements, the data types for elements and attributes. In DBMS, Schema is a description of a database structure. Internal structures such as tables and fields can be defined using schemas. Schema defines tables and fields that make up the data. Schemas are defined using constraints.
There are two types of constraints:
1. CONTENT CONSTRAINTS
An XML schema is a set of schema components in which there are 13 kinds of grouped components under 3 categories primary, secondary and helper components.
The primary components include
* SIMPLE TYPE DEFINITIONS
An XML schema consists of components such as type definitions and element
declarations. They are used to access the validity of the well-formed
element and attribute information items.
XML schemas are successors of the DTDs. XML schemas are extensible,
richer and more useful than DTDs. XML schemas can support data types
and name spaces. The difference between the schemas and DTDs are:
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