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Management Information Systems, Sixth Edition
Chapter 7: Databases and Data Warehouses
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Objectives Explain the difference between traditional file organization and the database approach to managing digital data Explain how relational and object-oriented database management systems are used to construct databases, populate them with data, and manipulate the data to produce information Enumerate the most important features and operations of a relational database, the most popular database model Management Information Systems, Sixth Edition
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Objectives (continued)
Understand how data modeling and design creates a conceptual blueprint of a database Discuss how databases are used on the Web List the operations involved in transferring data from transactional databases to data warehouses Management Information Systems, Sixth Edition
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Shine in 10 (Activity 7) Define IYOW any of the following that is assigned to you: Database approach vs Traditional file approach Hierarchy of Data (Show the hierarchy and examples) Primary, Composite and Foreign keys SQL (what it does and how it works) ERD (how it is used – be specific) Data Warehouse This is worth 20pts Management Information Systems, Sixth Edition
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Managing Digital Data Businesses collect and dissect data for many purposes Data can be stored in database format Easy access and manipulation Databases have had a profound impact on business An information industry has been created Database technology integrated with the Internet has contributed to commerce significantly Management Information Systems, Sixth Edition
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The Traditional File Approach
Traditional file approach: no mechanism for tagging, retrieving, or manipulating data Database approach: provides powerful mechanism for managing and manipulating data Traditional approach is inconvenient: Program-data dependency High data redundancy Low data integrity Data redundancy: duplication of data Data integrity: accuracy of data Management Information Systems, Sixth Edition
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The Traditional File Approach (continued)
Management Information Systems, Sixth Edition
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The Database Approach Database approach: data organized as entities
Entity: an object about which an organization chooses to collect data, such as: People Events Products Character: smallest piece of data A single letter or a digit Field: single piece of information about entity Management Information Systems, Sixth Edition
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The Database Approach (continued)
Record: collection of related fields File: collection of related records Database fields can hold images, sounds, video clips, etc. Field name allows easy access to the data Database management system (DBMS): program used to: Build databases Populate a database with data Manipulate data in a database Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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The Database Approach (continued)
Query: a message to the database requesting data from specific records and/or fields Database must be properly secured Not everyone should have access to all data Users will have different views of the database, based on the data they are allowed to see Management Information Systems, Sixth Edition
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The Database Approach (continued)
Visual Query from MS Access Management Information Systems, Sixth Edition
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The Database Approach (continued)
Database administrator (DBA): the person responsible for managing the database Sets user limits for access to data in the database DBMS is usually bundled with a programming language Management Information Systems, Sixth Edition 14 14
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Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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Database Models Database model: general logical structure
How records stored in the database How relationships between records are established Database models differ in: How records are linked to each other How users can navigate the database, retrieve records, and create records Management Information Systems, Sixth Edition
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The Relational Model Relational Model: consists of tables
Based on relational algebra Tuple: record (or row) Attribute: field (or column) Relation: table of records To design a relational database, you must understand the entities to be stored in the database and how they relate Tables are independent of each other, but can be related to each other Management Information Systems, Sixth Edition
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The Relational Model (continued)
Key: a field whose values identify records Used to retrieve records Primary key: a field by which records are uniquely identified Each record in the table must have a unique key value Composite key: combination of fields that serve as a primary key Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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The Relational Model (continued)
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The Relational Model (continued)
Foreign key: a field that is common to two tables Used to link the tables This field is a primary key in one table and a foreign key in the other Join table: composite of tables Two types of table relationships: One-to-many relationship: one item in a table is linked to many items in the other table Many-to-many relationship: many items in a table are linked to many items of the other table Management Information Systems, Sixth Edition
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The Relational Model (continued)
Primary Key Foreign Key Related One-to-Many Table in MS Access Management Information Systems, Sixth Edition
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The Relational Model (continued)
Demo Management Information Systems, Sixth Edition
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The Object-Oriented Model
Object-oriented database model: uses object-oriented approach for the database structure Encapsulation: combined storage of data and relevant procedures to process it Allows object to be “planted” in different data sets Inheritance: the ability to create a new object by replicating the characteristics of an existing (parent) object Object-oriented databases (ODBs) store data objects, not records Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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Relational Operations
Relational operation: creates a temporary subset of a table or tables Used to create a limited list or a joined table list Three important relational operations: Select: a selection of records based on conditions Project: a selection of certain columns from a table Join: join data from multiple tables to create a temporary table Management Information Systems, Sixth Edition
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Structured Query Language
Structured Query Language (SQL): query language of choice for DBMSs Advantages of SQL: It is an international standard It is provided with most relational DBMSs It has easy-to-remember, intuitive commands Management Information Systems, Sixth Edition
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Structured Query Language
SQL in MS Access Management Information Systems, Sixth Edition
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Structured Query Language
Demo Management Information Systems, Sixth Edition
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The Schema and Metadata
Schema: a plan that describes the structure of the database, including: Names and sizes of fields Identification of primary keys Relationships Data dictionary: a repository of information about the data and its organization Also called metadata: the data about the data Management Information Systems, Sixth Edition
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The Schema and Metadata (continued)
Metadata includes: Source of the data Tables related to the data Field and index information Programs and processes that use the data Population rules: what is inserted, or updated, and how often Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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Data Modeling Databases must be carefully planned and designed to meet business goals Data modeling: analysis of an organization’s data and identification of the data relationships A proactive process Develops a conceptual blueprint of the database Entity relationship diagram: a graphical representation of all entity relationships Management Information Systems, Sixth Edition
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Building Blocks of ERD Type English Grammar Equivalent Example Entity
Proper Noun Student, Employee, Instructor, Courses, Room Relationship Verb has, teaches, belongs, handles Attribute Adjective Height, Age, Gender, Nationality, First name
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ERD Popular Notation Chen Notation Crow’s Foot Notation
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Chen Notation - Symbol Rectangle represents an Entity
Diamond represents a Relationship 1 M Lines with labels represents Cardinality
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Entity (Chen Notation)
is a real-world object distinguishable or unique from other objects. An entity can be a concrete or physical object like employee, student, faculty, customer etc. Or it could also be conceptual or abstract like transaction, order, course, subjects etc. It can be thought of as a noun like student, employee etc. It is normally represented by a rectangle shape.
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Database Background Entity could be a : Person Place Object Event
(ex. Teacher, Student, Physician) Place (ex. School, Hotel, Store ) Object (ex. Mouse, Books, Bulding ) Event (ex. Enroll, Withdraw, Order ) Idea or Concept (ex. Courses, Account, Delivery )
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Entity - Example Customer Sales Rep Order Parts
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Relationship is a way of relating one entity to another. Entities can therefore participate in a relationship. it is commonly thought as a verb connecting the entities or nouns. It is normally represented by a diamond shape.
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Relationship - Example
represents Customer Sales Rep has Could be read as : A Sales Rep Represents a Customer. And a Customer has an Order. Order
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Cardinality Cardinality: number of items that must be included in a relationship An entity in a relationship with minimum cardinality of zero plays an optional role in the relationship An entity with a minimum cardinality of one plays a mandatory role in the relationship
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Cardinality - Symbols One-is-to-many Relationship
1 M One-is-to-many Relationship M N Many-to-many Relationship
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Cardinality Symbols - Example
represents Sales Rep 1 M Customer Could be read as : A Sales Rep could represent 1 or Many Customers.
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Cardinality Symbols – Example (Cont’d)
has Order M N Parts Could be read as : An Order could have many Parts (e.g. Products Ordered) and a Part could have many Orders.
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Degree of Relationship
There are three Degree of Relationships in ERD notation, namely: Unary Binary Ternary
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Degree of Relationship (Cont’d)
Unary Binary Ternary
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Degree of Relationship (Cont’d)
Manages Unary Employee makes Customer Orders Binary Vendor Warehouse Ternary supplies Part
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Attribute Refers to the characteristic or basic fact or field of an Entity or Relationship. For example a Student entity could have the following attributes ID Number, Last Name, First Name, Address, Birth Date etc. A relationship could also have an attribute for example an Entity name Student enrolls (relationship) to a Course/Program. Now, when you enroll you enroll on a certain date so you will have an attribute of Enrollment Date under Enroll relationship. It is normally represented by an oval.
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Attribute - Example Sales Rep Take note that a Primary Key
Lastname Firstname RepNum Street City Sales Rep State Take note that a Primary Key is underlined. Rate Zip Commission
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Attribute – More Example
CustomerName CustomerNum Lastname Firstname RepNum Street Street represents City Sales Rep 1 M Customer City State State Rate CreditLimit Zip Zip Commission Balance
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Crow’s Foot notation - Symbol
Entity name Attribute 1 Attribute 2 Attribute 3 Attribute 4
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Crow’s Foot notation - Example
Entity Student StudentID Firstname Lastname Gender Program Attributes
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Crow’s Foot notation - Keys
Student PK – Primary Key StudentID (PK) Firstname Lastname Gender ProgramID (FK) FK – Foreign Key
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Crow’s Foot Cardinality - Symbols
One and only one included in the relationship Zero or many could be included in the relationship. This is optional mode. One or many could be included in the relationship. This is mandatory mode.
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Crow’s Foot notation – with Cardinality
Customer Rep Customernum(PK) Customername Street City State Zip Balance CreditLimit Repnum (FK) Repnum (PK) Firstname Lastname Commission Rate
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Mini-Project 2 – ERD Management Information Systems, Sixth Edition
Create an ERD for your Case Study in Gardeners+ that you started on chapter 1. Identity the different entities and the relationship among these entities. This is worth 50 points and below is the criteria on how are you going to be graded Criteria : ERD reflects real world entities or all entities are properly identified - 40% Relationships are well defined - 30% Attributes are complete and well defined - 30% TOTAL % Note : Make sure that standard of integrity is followed in your project as mentioned in our syllabus. Which means I expect that your work should be your work and not of the others. However, it does not mean you could not consult your classmates. You could consult one or two of your classmates but make sure that it is a matter of clarification or technicality. A high degree of similarity with at least one of your Classmates, I would consider as copying or plagiarism and therefore will be dealt with accordingly, that is, it would merit a deductions both on you and your classmate where you copied your work. Management Information Systems, Sixth Edition
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Mini-Project No. 3 - Database
Creating the Gardeners+ Database Create a Database for your case study based on your ERD that you have just created Create tables that reflects an entity, namely, People, Event or Products Create a relationship among tables You could use MS Access or MySQL Database Management Systems on this one. This is worth 50 points and the criteria for your grading is shown below: Criteria : Tables reflects real world entities - 40% Table Relationships are rightly defined - 40% Complete sets of tables are defined - 20% TOTAL % Note : Make sure that standard of integrity is followed in your project as mentioned in our syllabus. Which means I expect that your work should be your work and not of the others. However, it does not mean you could not consult your classmates. You could consult one or two of your classmates but make sure that it is a matter of clarification or technicality. A high degree of similarity with at least one of your Classmates, I would consider as copying or plagiarism and therefore will be dealt with accordingly, that is, it would merit a deductions both on you and your classmate where you copied your work. Management Information Systems, Sixth Edition
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Databases on the Web Web is dependent on databases
Organizations must link their databases to the Web Interface between Web and database required Interface may be programmed in one of several Web programming languages, including: Java servlets Active server pages (ASP) PHP (Hypertext Preprocessor) Web application program interfaces (APIs) Management Information Systems, Sixth Edition
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Databases on the Web (continued)
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Data Warehousing Most data collections are used for transactions
Accumulation of transaction data is useful Data warehouse: a large repository database that supports management decision making Typically relational Data is collected from transactional databases Data mart: a smaller collection of data focusing on a particular subject or department Management Information Systems, Sixth Edition
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From Database to Data Warehouse
Transactional databases are not suitable for business analysis Contain only current, not historical data Data warehouse requires large storage capacity: Mainframe computers are often used Scalability is an issue Data warehouses grow continually Management Information Systems, Sixth Edition
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Phases in Data Warehousing
Three phases in transferring data from a transactional database to a data warehouse: Extraction phase: create files from transactional database Transformation phase: cleanse and modify the data format Loading phase: transfer files to data warehouse A properly built data warehouse becomes a single source for all data required for analysis Data mining and online analytical processing (OLAP) use data in data warehouses Management Information Systems, Sixth Edition
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Management Information Systems, Sixth Edition
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Demo VB.net Database Demo
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MS Access Demo Demo Management Information Systems, Sixth Edition
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Summary Organizations collect vast amounts of data
Database approach has several advantages over traditional file approach Character: smallest piece of data Field: made up of multiple characters Record: collection of related fields File: collection of related records Database management system (DBMS): tool to construct databases Management Information Systems, Sixth Edition
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Summary (continued) Relational and object-oriented database models have different advantages Keys are used to form links among entities Primary keys are unique identifiers Object-oriented database maintains objects that contain data and procedures that process it Structured Query Language (SQL) is an international standard for querying databases Database designer must construct a schema to construct a database Management Information Systems, Sixth Edition
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Summary (continued) Database designers conduct data modeling and create entity relationship diagrams to plan databases Many databases are linked to Web Data warehouses contain huge collections of historical transaction data Data warehouse requires data extraction, transformation, and loading of transactional data Invasion of privacy is exacerbated by database technology Management Information Systems, Sixth Edition
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