IE 423 – Design of Decision Support Systems Data modeling and database development.

IE 423 – Design of Decision Support Systems

Data modeling and database development

By now you should have

Read Chapters 1,2,3, 4, and 5 in Pol and AhujaAlso, read chapter 6 in Pol and Ahuja

DataBase Development

We have looked at ways to model data oriented problems and databases to help solve these problemsThe next step is to turn these models into real databasesRelational models give us relational schemas,…From these we can create the actual data base


We are going to skip an important topic Normalization

…but, will get to this topic very soon


Microsoft Access Relational Database

Management System – RDBMS

Database definitionDatabase creationDatabase managementDatabase manipulation


Microsoft Access Same genre of application as Oracle, DB2,

MySQL, PostGres, MS SQLServer… We use it because…

Easy to use Popular, widely used particularly in academia,

small to medium sized businesses Available Well integrated with other MS Office applications Supports standard data manipulation language

Maybe not “industrial strength” as some


Microsoft Access Conceptually, everything we will

learn with access will apply to other RDBMS systems…

…but the techniques may be different

What we will do with Access will be very migratable to other RDBMSs


Microsoft Access Architecture Access database is a collection of

data objects In part, these data objects

correspond to the entities/objects that we discussed in modeling

Access has a few more that we did not discuss


Microsoft Access Architecture Some primary objects and

concepts that we will be concerned aboutTablesRelationshipsQueriesForms and Reports


Microsoft Access – Work Environment

Getting Started The task pane Lets you open

an existing database, or

Create a new one

Task

Pane



Object Panel Shows types of

Objects in database

Select an object type (Tables, Queries, etc.)…

Access will show you the objects of that type in the DB



Object Panel Note that we

have the list of existing tables in the DB, but …

We also have three tools for creating a new object of that type (table)


Microsoft Access – Work Environment Just like Excel (and Word, and PowerPoint) we

usually have two or three ways to do anything Menus (File, Edit, Insert, Format) Toolbars (standard, formatting, web,…) Tool icons (DesignView, DatasheetView,…) Key combos Function keys

You can customize toolbars Go to View on menu bar Click on Toolbars…, then Customize Check each toolbar that you want to be present


Microsoft Access – Tables Most databases in Access (and any other RDBMS)

has multiple tables A table is a RDBMS representation of a relation

(remember: 2D grid attributes and instances) Columns are attributes – we will start calling these -

fields Rows are entity instances – we will start calling them

records

DataBase DevelopmentMicrosoft Access – Tables

Work directly with tables in two modes

Datasheet View or Design View

Datasheet View Shows table as a data

grid Contains columns

(attributes), and… Rows (instances or

records) Good for editing,

entering data Not so good for

creating or modifying the structure of the table


Design View For the creation of

the table Or to view the

tables definition Two part window

Top – field definitions

Bottom – field properties


Switch between Design View and Datasheet View – use View tool

Or View on main menu

DataBase DevelopmentMicrosoft Access – Relationships

Defines relationships (clever name, huh!) between and among tables

Should have some unifying field, a field in common in tables being related

This is how Access will find related information

DataBase DevelopmentMicrosoft Access – Relationships

This is where we define

One-to-One One-to-Many Many-to-Many Relations that we

discussed under modeling

DataBase DevelopmentMicrosoft Access – Queries

There are several kinds of queries Select Queries Update Queries Insert Queries Delete Queries


Select Queries – Select data from other data objects These objects can be other tables Can be multiple tables Can be from other queries Can be from combination of tables and queries


There are several kinds of queries

Select Queries Update Queries Insert Queries Delete Queries

DataBase DevelopmentMicrosoft Access

Select Queries – Select or pull a subset of data from a dataset

Subset may be from a single relation or from a relationship


Insert Queries – adds instances (records) to a relation or relationship

Add a new product to a databaseAdd a new path to a routing

application


Append Queries – add sets of data to other sets of data

Add this week’s new transaction to master archive

Add a set of system access records to a master log database

IE 423 – Design of Decision Support Systems Data modeling and database development.

Documents

existing database

object type tables

collection of data objectsin

data oriented problems

database developmentby

new object

list of existing tables

rdbms representation