Page 1 ISMT E-120 Introduction to Microsoft Access & Relational Databases The Influence of Software and Hardware Technologies on Business Productivity

Page 2 The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization Introduction to Microsoft Access & Relational Databases

Page 3 The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization Introduction to Microsoft Access & Relational Databases

Page 4 Database Basics 1.Database is made up of 1 or more tables containing data 2.Tables have fields, also called columns 3.Tables have rows, also called records 4.Record is a set of fields in a row

Page 5 Query Basics Query means get data from which fields from which rows Query Engine o Connects database to a data source o Allows us to choose from tables or queries saved in database Access o Use a design grid to create queries o Drag-and-drop or write SQL

Page 6 Entity Basics Key concept – types of info in the database What are they? o Subject of the database o Subject of each table o Nouns (person, place, thing) o Important topics o Unique representation of a single real- world object

Page 7 Examples of Entities Grade Database o Instructors o Classes o Assignments o Students o Enrollments o Results o Grades Music Collection Database o Music genres o Music mediums o Artists o Song Titles o Instruments o Year recorded

Page 8 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Page 9 What is a Relational Database? A database is made up of tables Relationships link tables together Simple database = 1 subject Complex database = many subjects 1 subject = 1 entity per table

Page 10 Table Relationships Use verbs to describe a relationship between tables/entities/subjects Linkages Types of relationships  one-to-one  one-to-many**  many-to-many **Most common and almost always best

Page 11 Examples of Relationships Instructors Teach Classes Students Enroll in Classes Classes Require Assignments Students Submit Assignments Students Receive Results

Page 12 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Page 13 Designing Databases Understand the application you’re building Identify data elements

Page 14 Design: Understand the Business Application Document sequence of steps Map information flows Identify decision points View from user or audience perspective

Page 15 Design: Identify Data Elements Might use: Manual Input Forms Reports Interviews General Knowledge

Page 16 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Entity Relationship Analysis 1.Identify distinct, relevant entities; name them and identify a primary key 2.Determine relationships between entities – describe them as verbs in whole sentences; create new entities as needed 3.Add appropriate attributes to entities; if an attribute has repeating values, create a new entity with a 1-to-many relationship Page 17

Entity Relationship Analysis Refer to ERA handout Page 18

Page 19 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Page 20 Database Objects Tables Queries Forms Reports Macros Others Build a database

Page 21 Tables One Table, One Entity/Topic/Subject Base or reference tables Made up of fields/attributes Must have a primary key Same key in more than one table to link them – primary key in one table and foreign key in second table

Page 22 Queries Types of Queries Select - get data out (view, export …) Append – add data to existing table Update - change existing data Delete - delete data SQL does the work

Page 23 Writing Queries Choose Tables Choose Fields Sort Filter with Criteria Use Parameters

Page 24 Forms Customary user interface Base on a table or query Forms help users to: o View data o Insert data o Update data o Delete data

Page 25 Creating Forms Based on tables Walk through table one row at a time Based on queries More powerful Manage data from several tables at once Use form wizard or design palette

Page 26 Reports Presents data in an easy to read, attractive manner Can be based on a table or query Format query results One query can be used for multiple reports One report can be made from multiple queries

Page 27 Creating Reports Can be based on tables Can be based on queries More powerful Link several tables at once Select fields Add calculations, etc.

Page 28 Macros Stored Sequence of Operations Can be executed any time Easy to use interface to create them

Page 29 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Page 30 Create An Access Database What’s the topic/subject/entity of the database? Define Tables and Keys

Page 31 Create An Access Database Establish Relationships –Link All Tables –Database Tools  Relationships… –Relationship Properties –Relationships Carry Over to Queries

Page 32 Create An Access Database Create queries for use with forms and reports Develop forms Write reports

Page 33 Introduction to Microsoft Access & Relational Databases The Basics – Database, Query & Entity Relational Databases Database Design Entity Relationship Analysis Database Objects Create a Database Normalization

Page 34 What is Normalization? Process to Eliminate Redundancy Group Data Items into Manageable Collections Verify Completeness of Data

Page 35 Benefits of Normalization Easier to Maintain Information Easier to Query Database Extensible Design Promotes Data Integrity

Page 36 Normalization: Step 1 List Every Data Item in One Table Columns/fields Rows/records 1 Cell = 1 Piece of Data Add Duplicate Information as Needed Find or Create a Primary Key A field or combination of fields uniquely identifying each row This is First Normal Form

Page 37 Normalization: Step 2 Which Keys Determine Which Fields? Functional dependencies One key value determines one field value May be > 1 Set of Keys Break Into Separate Tables According to Functional Dependencies This is Second Normal Form

Page 38 Normalization: Step 3 Look for Functional Dependencies Among Non-Key Fields Remove Any Dependent Non-Key Fields Make Sure No Loss of Information i.e., fields should be in some other table Third Normal Form

Page 39 Normalization Sanity Check Make Sure No Information Lost Make Sure Tables “Connect” One-to-one One-to-many NOT many-to-many Make Sure Keys are Unique Referential Integrity