5. ID Name GPA College
C44011257 Sam 3.5 NCKU
H33014542 John 3.1 NTU
H45143215 Amy 3.3 Stanford
D31545344 Angelababy 3.8 MIT
她長這樣
• Table Student
Name State Enr(NTD)
NCKU Tainan 4,5000
NTU Taipei 50,000
Stanford CA 1,500,000
MIT CA 2,000,000
• Table College
18. Relational Model XML
Structure Table Hierarchical, Tree,
graph
Schema Fixed in advance Flexible
“Self-describing”
Query Simple, nice
Language
Less so
Ordering None Implied
Implementation Native Add-on
XML versus Relational Model
19. Q&A
Q1:
A database to contain information about university records:
students, courses, grades, etc.
Should you use the relational model or XML?
Q2:
A database to contain information for a university web site:
news, academic announcements, admissions, events, research,
etc.
Should you use the relational model or XML?
20. Well Formed的XML 文檔遵守的語法規則:
• XML 文檔必須有根元素
• XML 文檔必須有關閉標籤
• XML 標籤對大小寫敏感
• XML 元素必須被正確的嵌套
• XML 屬性必須加引號
Well-formed XML vs. Valid XML
Valid的XML 文檔遵守的語法規則:
遵守DTD和XSD的架構特定規範和內容特定規範
XML 文件
Validation XML
parser
Parsed
XML
DTD
XSD