Relational data models
- First introduced in a paper in 1970
Created by E.F. Codd An IBM engineer
The model used mathematics known as relational algebra.
A relational database consists of a collection of tables connecting via relationships.
Each table (or
Username: ALAN BRANDYBERRYBook: Database Processing: Fundamentals, Design, and Implementation, Thirteenth
Edition. No part of any book may be reproduced or transmitted in any form by any means without the publisher's prior
written permission. Use (other t
an object-oriented computer programming
language commonly used to create
interactive effects within web browsers.
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Extended diagram rules
Ensure that ERD notation is correctly used
Similar to syntax rules for a computer language
Consistency rules: no conflicts among specifications
Supported by the ER Assistant
Relationship/Entity Connection Rule: relationships connect
- Accepts data from its environment, processes data, and produces output data for decision making
- Interacts with environment
- Database provides the long-term memory
- Database is a key component but not the only co
Intro to SQL
- Query: request for data to answer a question
Indicate what parts of database to retrieve not the procedural details
Improve productivity and improve accessibility
SQL SELECT statement and graphical tools
Combine procedural language with non
Basic Query Formulation
- SELECT <list of column expressions>
FROM <list of tables and join operations>
WHERE <list of logical expressions for rows>
ORDER BY <list of sorting specifications DESC>
cfw_Default sorting order is ASC
Column expression: combina
Developing business data models
The simplicity principle should be applied during the search for entity types in the initial ERD, especially
involving choices between attributes and entity types. Unless the problem description contains
Diagram rules are similar to syntax rules for a programming language
- Apply rules to ensure complete and consistent diagrams
- Review parts 1 and 2 of Unit 3 by focusing on diagram rules
- Use the ER Assistant to check ERDs
Extended Query Formulation
Columns in result
Conditions to test (including join conditions)
How to combine the tables?
Usually join of PK to FK
More complex ways to combine
Individual rows or groups of rows?
Aggregate functions in result
Logical database design
Identify possible redundancy
Eliminate unwanted redundancy
Support organizational policies
Managing redundancy is a major theme of logical database design.
Eliminating unwanted redundancy is an important data qua
Intro to database
- Databases crucial for daily operations and decision making in organizations.
Database management technologies:
Major part of software industry
Revolutionary evolvement over 40 years
Foundation for management of long term memory of orga
IF, after carefully following the directions below, you run the procedure
and receive only this as output:
Connecting to the database [your connection name].
Disconnecting from the database [your connection name].
In your SQL D