Types of Data Models Conceptual Data Models Implementation

ประเภทของแบบจำลองขอมล (Types of Data Models) Conceptual Data Models Implementation Data Models

พนฐานการสรางแบบจำลองขอมล (Data Models Basic Building Blocks) Entities Attributes Relationships Constraints

พนฐานการสรางแบบจำลองขอมล (Data Models Basic Building Blocks) - ความสมพนธระหวาง Entities 1: 1 1: M Attributes M : M หรอ M : N Relationships Constraints

แบบจำลองฐานขอมล (Database Model) Hierarchical Database Model Network Database Model Relational Database Model Object-Oriented Database Model Multidimensional Database Model

โครงสรางขอมลเชงสมพนธ (Relational Data Structure) Primary Key : PK Attribute (Field, Column) Cardinality Tuple (Record, Row) Relation (Table, File) Degree Domain : Rang of Data in each Field Foreign Key : FK

กฎ 12 ขอของคอดด (Codd’s 12 Relational Database Model) • • • Information Guaranteed Access Systematic Treatment of Null Dynamic On-Line Catalog Based on the Relational Model Comprehensive Data Sublanguage View Updating High-Level Insert, Update and Delete Physical Data Independence Logical Data Independence Integrity Independence Distribution Independence Nonsubversion

คย (Keys) Candidate Key : CK Primary Key : PK Alternate Key / Secondary Key Foreign Key : FK Composite/Concatenated/Compound Key Super Key