Learning objectives of this chapter include: Learn how to transform E-R data models into relational designs; practice the normalization process from chapter 2; understand the need for denormalization, learn how to represent weak entities with the relational model; know how to represent 1:1, 1:N, and N:M binary relationships. | Database Design Chapter Five DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 3rd Edition Chapter Objectives Learn how to transform E-R data models into relational designs Practice the normalization process from Chapter 2 Understand the need for denormalization Learn how to represent weak entities with the relational model Know how to represent 1:1, 1:N, and N:M binary relationships 5- Chapter Objectives (continued) Know how to represent 1:1, 1:N, and N:M recursive relationships Learn SQL statements for creating joins over binary and recursive relationships Understand the nature and background of normalization 5- Transforming a Data Model into a Relational Design 5- Representing Entities with the Relational Model Create a relation for each entity A relation has a descriptive name and a set of attributes that describe the entity Specify a primary key Specify column properties Data type Null status Default values (if any) Data constraints (if any) The relation is then analyzed using the normalization rules As normalization issues arise, the initial relation design may need to change 5- Representing an Entity as a Table ITEM (ItemNumber, Description, Cost, ListPrice, QuantityOnHand) 5- Normalization Review: Modification Problems Tables that are not normalized will experience issues known as modification problems Insertion problems Difficulties inserting data into a relation Modification problems Difficulties modifying data into a relation Deletion problems Difficulties deleting data from a relation 5- Normalization Review: Solving Modification Problems Most modification problems are solved by breaking an existing table into two or more tables through a process known as normalization 5- Normalization Review: Definition Review Functional dependency The relationship (within the relation) that describes how the value of a one attribute may be used to find the value of another attribute Determinant The attribute that can be used to find the | Database Design Chapter Five DAVID M. KROENKE and DAVID J. AUER DATABASE CONCEPTS, 3rd Edition Chapter Objectives Learn how to transform E-R data models into relational designs Practice the normalization process from Chapter 2 Understand the need for denormalization Learn how to represent weak entities with the relational model Know how to represent 1:1, 1:N, and N:M binary relationships 5- Chapter Objectives (continued) Know how to represent 1:1, 1:N, and N:M recursive relationships Learn SQL statements for creating joins over binary and recursive relationships Understand the nature and background of normalization 5- Transforming a Data Model into a Relational Design 5- Representing Entities with the Relational Model Create a relation for each entity A relation has a descriptive name and a set of attributes that describe the entity Specify a primary key Specify column properties Data type Null status Default values (if any) Data constraints (if any) The relation is then .
