4/16/2007 Declare a Schema File I 1
Declare a Schema File I
4/16/2007 Declare a Schema File I 2
Declare a Schema File
• A collection of semantic validation rules designed to constrain XML data values
• Reasons to choose Schema over DTDs
4/16/2007 Declare a Schema File I 3
Declare a Schema File
• The syntax of schema
4/16/2007 Declare a Schema File I 4
An Example
4/16/2007 Declare a Schema File I 5
Schema
4/16/2007 Declare a Schema File I 6
Add a Comment
• Comment cannot appear in
4/16/2007 Declare a Schema File I 7
Contain Other Elements
4/16/2007 Declare a Schema File I 8
Contain Other Elements
4/16/2007 Declare a Schema File I 9
Contain Other Elements
4/16/2007 Declare a Schema File I 10
4/16/2007 Declare a Schema File I 11
Contain Other Elements
4/16/2007 Declare a Schema File I 12
Declare One-Time Element
• A given element is associate with one – and only one – value at runtime
• Also called a required element
4/16/2007 Declare a Schema File I 13
Declare One-Time Element
4/16/2007 Declare a Schema File I 14
Declare One-Time Element
4/16/2007 Declare a Schema File I 15
Declare Optional Elements
4/16/2007 Declare a Schema File I 16
Declare Optional Elements
4/16/2007 Declare a Schema File I 17
Declare Repeatable Elements
4/16/2007 Declare a Schema File I 18
Declare Repeatable Elements
4/16/2007 Declare a Schema File I 19
Contain Character Data
4/16/2007 Declare a Schema File I 20
Contain Character Data
4/16/2007 Declare a Schema File I 21
Contain Character Data
4/16/2007 Declare a Schema File I 22
Contain Character Data
4/16/2007 Declare a Schema File I 23
Declare Empty Element
4/16/2007 Declare a Schema File I 24
Declare Empty Element
4/16/2007 Declare a Schema File I 25
Declare Empty Element
• Conceptually, elements represent data, while attributes represent metadata, or “data about data.”
• In other word, elements model essential information; attributes model descriptive information.
• Associating attributes with an element defined as empty is fairly common practice.
4/16/2007 Declare a Schema File I 26
Declare Empty Element
4/16/2007 Declare a Schema File I 27
Contain Mixed Value
• Declare a schema validation rule that allow an XML element to contain both– Character data– Other predefined elements
4/16/2007 Declare a Schema File I 28
Contain Mixed Value
4/16/2007 Declare a Schema File I 29
Contain Mixed Value
4/16/2007 Declare a Schema File I 30