TAILIEUCHUNG - Lecture Fundamentals of database systems: Chapter 7 - Emasri, Navathe

Chapter 7 discusses how to design a relational database schema based on a conceptual schema design. This chapter presented a high-level view of the database design process, and in this chapter we focus on the logical database design or data model mapping step of database design. We present the procedures to create a relational schema from an Entity-Relationship or an Enhanced ER schema. | Chapter 7 Copyright 2007 Ramez Elmasri and Shamkant B. Navathe ER-to-Relational Mapping Algorithm Step 1 Mapping of Regular Entity Types Step 2 Mapping of Weak Entity Types Step 3 Mapping of Binary 1 1 Relation Types Step 4 Mapping of Binary 1 N Relationship Types. Step 5 Mapping of Binary M N Relationship Types. Step 6 Mapping of Multivalued attributes. Step 7 Mapping of N-ary Relationship Types. Mapping EER Model Constructs to Relations Step 8 Options for Mapping Specialization or Generalization. Step 9 Mapping of Union Types Categories . Step 1 Mapping of Regular Entity Types. For each regular strong entity type E in the ER schema create a relation R that includes all the simple attributes of E. Choose one of the key attributes of E as the primary key for R. If the chosen key of E is composite the set of simple attributes that form it will together form the primary key of R. Example We create the relations EMPLOYEE DEPARTMENT and PROJECT in the relational schema corresponding to the regular entities in the ER diagram. SSN DNUMBER and PNUMBER are the primary keys for the relations EMPLOYEE DEPARTMENT and PROJECT as shown. Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Slide 7- 3 Copyright 2007 Ramez Elmasri and Shamkant B. Navathe lide 7-4 Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Slide 7- 5 1 Step 2 Mapping of Weak Entity Types For each weak entity type W in the ER schema with owner entity type E create a relation R include all simple attributes or Simple components of composite attributes of W as attributes of R. Also include as foreign key attributes of R the primary key attribute s of the relation s that correspond to the owner entity type s . The primary key of R is the combination of the primary key s of the owner s and the partial key of the weak entity type W if any. Example Create the relation DEPENDENT in this step to correspond to the weak entity type DEPENDENT. Include the primary keySSNof the EMPLOYEE relation as a foreign key .

• Cơ sở dữ liệu
• Fundamentals of Database Systems
• Database Systems
• Relational database design
• EERR to Relational mapping
• Mapping EER model constructs
• ER to Relational mapping algorithm
• Database system concepts
• The relational data model
• Database design
• Database programming techniques
• Relational database constraints
• Database architecture
• Data models
• Hierarchical model
• Relational database design algorithms
• Designing a set of relations
• Relational decompositions
• Relational database schema
• Database users
• Database applications
• Typical DBMS functionality
• Database approach
• Databases and database users
• Relational databases
• Relational calculus
• Physical database design
• Concurrency control techniques
• Database recovery techniques
• Database security
• Distributed databases
• Database management systems
• Fundamentals of database management systems
• Logical database design
• Object oriented database management
• Data administration
• Relational model concepts
• Relational model constraints
• Characteristics of relations
• Database design process
• ER model concepts
• ER diagrams
• Database application
• Relational database schemas
• Multivalued dependencies
• Database design theory
• File structures
• Query processing
• Database tuning
• Transaction processing
• Concurrency control
• Database System
• Lecture Database Systems
• Enhanced Entity Relationship
• UML modeling
• Enhanced ER model
• Fundamentals of data modeling
• Data modeling
• Entity Relationship
• Relational algebra
• Relational model
• Programming techniques
• Database programming
• SQL Triggers
• Views in SQL
• Data independence
• Database system utilities
• Classification of DBMSs
• Embedded SQL
• Functions calls
• Stored procedures
• Relational data retrieval
• Relational database model