Data Models A collection of tools for describing 。Data ·Data relationships ·Data semantics ·Data constraints ■Relational model Entity-Relationship data model(mainly for database design) Object-based data models (Object-oriented and Object-relational) Semi-structured data model (XML) ■Other older models: ·Network model ·Hierarchical model Database System Concepts-7th Edition 1.10 ©Silberscha乜，Korth and SudarshanDatabase System Concepts - 7 1.10 ©Silberschatz, Korth and Sudarshan th Edition Data Models ▪ A collection of tools for describing • Data • Data relationships • Data semantics • Data constraints ▪ Relational model ▪ Entity-Relationship data model (mainly for database design) ▪ Object-based data models (Object-oriented and Object-relational) ▪ Semi-structured data model (XML) ▪ Other older models: • Network model • Hierarchical model