... Outline RelationalModel Concepts RelationalModel Constraints and RelationalDatabase Schemas Update Operations and Dealing with Constraint Violations RelationalModel Concepts The relational ... the relational approach in this chapter Relational Model Concepts The model was first proposed by Dr E.F Codd of IBM in 1970 in the following paper: "A RelationalModel for Large Shared Data ... arbitrarily to be the primary key The primary key attributes are underlined Key Constraints Entity Integrity RelationalDatabase Schema: A set S of relation schemas that belong to the same database...
... 2008 RelationalDatabaseDesign and Implementation Louis Davidson With Kevin Kline, Scott Klein, and Kurt Windisch 8662FM.qxp 7/28/08 6:19 PM Page ii Pro SQL Server 2008 RelationalDatabaseDesign ... CHAPTER Introduction toDatabase Concepts s CHAPTER The Language of Data Modeling 33 s CHAPTER Conceptual Data Modeling ... xxiii s CHAPTER Introduction toDatabase Concepts DatabaseDesign Phases Conceptual...
... when it comes to the concepts and basic theories that are fundamental to proper databasedesignDatabaseDesign Phases Too often when I sit down to build a system that requires data storage, the ... poor databasedesign or add features missing from the database No role is more critical to any datacentric application than the role of the data modeler User interfaces come and go, but data ... writing Purpose of DatabaseDesign What is the purpose of database design? Why the heck should you care? The main reason is that a properly designed database is straightforward to work with, because...
... Metadata Metadata is data stored to describe other data Knowing how to find information about the data stored in your system is very important Codd’s fourth rule states the following: The database ... your system, certainly as they pertain to the process of creating a database and the datato be stored in the database Often, no specific tool is used to document these rules, other than Microsoft ... hold, back up, and subsequently restore data when necessary It does not limit you to accessing data within only that one database; however, managing data in separate databases becomes a more manual...
... her name, so in the actors database they add a uniquifier to the name to make it unique A uniquifier might be some meaningless value added to a column or set of columns to give you a unique key ... If you happen to hire two people called Sir Lester James Fredingston III, then the second of them probably isn’t going to take kindly to being called Les for short just so your database system ... that is definitely going to allow you to uniquely identify every row in your database One thing of interest here is that what might be considered a natural key in your database is often not actually...
... relationaldatabase product before to learn why relational databases are designed in the way they are, and get some practical examples and advice for creating databases Topics covered cater to ... of database design? The first five chapters of this book are devoted to the fundamental tasks of relationaldatabasedesign and preparing your mind for the task at hand: designing databases The topics ... the need todesign a relationaldatabase using any of the Microsoft SQL Server family of databases It is intended to be useful for the beginner to advanced programmer, either strictly database...
... information model is a conceptual design for a database It describes the concepts to be stored in the database Implementation of a databasefrom an information model The vast majority of relationaldatabase ... a CASE tool, one designs the database, then connects to a data source, and then has the CASE tool issue the data definition queries to build the database Documentation of the databasedesign ... printed from the CASE tool Subsequent changes to the databasedesign can be made in the CASE tool and then applied to the database itself The workhorse for most database applications is data retrieval...
... The ER conceptual schema diagram for the COMPANY database FIGURE 7.2 Result of mapping the COMPANY ER schema into a relational schema ER -to- Relational Mapping Algorithm (cont) Step 2: Mapping ... customary to specify a new key attribute, called a surrogate key, when creating a relation to correspond to the category – In the example below we can create a relation OWNER to correspond to ... 4.7 to relations Mapping Exercise Figure 7.7 shows an ER schema for a database that may be used to keep track of transport ships and their locations for maritime authorities Map this schema into...
... right-hand-side attributes are in Ri 1 Informal Design Guidelines for Relational Databases (1) What is relationaldatabase design? The grouping of attributes to form "good" relation schemas Two levels ... are hard to understand or to detect The database designers need not normalize to the highest possible normal form (usually up to 3NF, BCNF or 4NF) Denormalization: the process of storing the ... level – The storage "base relation" level Design is concerned mainly with base relations What are the criteria for "good" base relations? Informal Design Guidelines for Relational Databases...
... for RelationalDatabase Schema Design (7) Discussion of Normalization Algorithms: Problems: The database designer must first specify all the relevant functional dependencies among the database ... join property with respect to F 2 Algorithms for RelationalDatabase Schema Design (1) Algorithm 11.2: Relational Synthesis into 3NF with Dependency Preservation (Relational Synthesis Algorithm) ... schema to ensure the attribute preservation property Claim 3: Every relation schema created by Algorithm 11.2 is in 3NF Algorithms for RelationalDatabase Schema Design (2) Algorithm 11.3: Relational...
... Although the term database typically refers to a collection of related data tables, an Access database includes more than just data In addition to tables, you can add: •Saved queries (stored procedures) ... Summary Data storage principles Attempt to store data time / place; Do not store data that may be calculated from other fields (utilize queries); and Strive for very discrete data storage (no ambiguity ... reports together to build a data software application Designto the lowest common denominator (Murphy will use your program early and often) Always look for and design carrots to win over the true data...
... for RelationalDatabase Schema Design (7) Discussion of Normalization Algorithms: Problems: The database designer must first specify all the relevant functional dependencies among the database ... schema to ensure the attribute preservation property Claim 3: Every relation schema created by Algorithm 11.2 is in 3NF Algorithms for RelationalDatabase Schema Design (2) Algorithm 11.3: Relational ... { CD, BE, ABC} Algorithms for RelationalDatabase Schema Design (2) Consider the relation scheme R= {ABCDEG} subject to FDs F= { A→B, BC → D, D → EG } Convert R into a 3NF scheme STEP R={ABCDEG}...
... diagrams shown below are taken from the example answers for Question and of the Chapter 11 Entity-Relationship Modeling Tutorial However, for the purposes of this tutorial, the attributes associated ... reorderLevel inStock PartOf 1 Customer Order ordeNo (PK} status dateDue /totalPrice Places * 1 custNo {PK} name fName lName address street city postcode telNo creditLimit Present a relational schema ... RelatedTo * Dependent dName {PPK} dAddress relationship (b) Product OrderDetails Requires qty status /totalPrice 1 * * prodNo {PK} desc price cost numberAllocation reorderQty reorderLevel inStock...
... Data Modeling and DatabaseDesign 8Ć7 8Ć8 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder DatabaseDesign Designing a relationaldatabase system involves converting a model into ... relationship model D Translate an entity relationship model into a relationaldatabasedesign Overview of Data Modeling and DatabaseDesign 8Ć3 Class Management Note: This lesson is an overview to the ... that it refers to a PK or UK Overview of Data Modeling and DatabaseDesign 8Ć27 8Ć28 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder Designing the Database The databasedesign stage...
... application had to emulate the decision making of an application engineer when responding to queries fromdesign engineers who wished to select a product with particular attributes for use in the design ... developers to create a model of the original case; however, like all models it is an abstraction from the complex reality of the domain of interest Contrary to initial claims, it was clear to the ... with social actors’ competencies in attempting to comprehensively communicate or represent their knowledge In addition, actors might just be too busy to document what they know due to the complexity...
... 12 Activity 3.2: Relating Data Requirements to Conceptual Design Exercise 1: Analyzing Your Own Experience of Conceptual Design ! Compare your experience with the concepts ... that has to service many users simultaneously Reflect on the process that you used to create a conceptual design for the project Then answer the following questions: a How is conceptual design ... development project, pick any other type of project that involved some activities related to conceptual datadesign For example, creating a little-league sports roster, a scoring or organization...
... a relationaldatabase and its components D Read an entity relationship model D Translate an entity relationship model into a relationaldatabasedesign Overview of Data Modeling and DatabaseDesign ... activities that you perform to achieve the best possible databasedesignDatabaseDesignDatabasedesign is just one of the stages of the development cycle Through good database design, you can achieve ... of Data Modeling and DatabaseDesign 8Ć9 Server ÉÉ ÉÉ ÉÉ ÉÉ 8Ć10 Introduction to Oracle: SQL and PL/SQL Using Procedure Builder DataModel Models are a cornerstone of design Engineers build a model...