Upload
erin-griffith
View
222
Download
2
Tags:
Embed Size (px)
Citation preview
INTRO TO DATABASESPart I
IS 340
BY
CHANDRA S. AMARAVADI
2
IN THIS PRESENTATION..
Entity classes, entities, attributes Database organization
file, record, attribute/field DBMS activities and functions DBMS components Importance of databases
NEED FOR DATABASES
A church needs to maintain information on A church needs to maintain information on donationsdonations A consulting company needs to manage its contactsA consulting company needs to manage its contacts A doctor needs to know if a patient is allergic to a A doctor needs to know if a patient is allergic to a particular medication.particular medication. An airline exec needs to know occupancy on a An airline exec needs to know occupancy on a flight.flight.
4
BASIC DATA CONCEPTS
5
THERE ARE THINGS ANDOBJECTS IN THE REAL WORLD
These are called entities.
WE ARE MORE INTERESTED IN
Organization
Eclasses
Produce customers
Sales/vendorsmachines/parts
7
ENTITY CLASSES HAVE PROPERTIES
Properties are calledattributes
Produce customers
Sales/vendorsmachines/parts
Barcode#, price per unit, supplier, total qty
8
DISCUSSION
Classify the following as entity, entity class or attribute
John San Francisco (as a city) Customer Book Store# Nintendo DS Microsoft Microsoft employees The book “Great Expectations” Invoice Production
9
BASIC ORGANIZATION CONCEPTS
10
DATA VS INFORMATION
Data about an entity are raw facts. Are they useful?
December 30th, 1984Played for Cavs and Heat
Born March 28th , 198615m albums sold
Car driven by Bobby Redhall
11
INFORMATION IS USEFUL IF COMPLETE
Example information about a person
Name: Chris NashDOB: 2-4-1965 Profession: EngineerAddress: 415 Walnut street.
This describes a personmore. It is called ????.
12
ANOTHER EXAMPLE
Example information about a credit card transaction:
Acct#: 4555950Date: 12/5/08Time: 4:48 pmMerchant: WIU UnionCard type: Master CardIssuer: First Bank
This describes a transactionmore.
13
ONE ATTRIBUTE HAS A UNIQUE VALUE
Which of these has a unique value?
Acct#: 4555950Date: 12/5/08Time: 4:48 pmMerchant: WIU UnionCard type: Master CardIssuer: First Bank
The unique attribute iscalled ???
3300 3305 3313
14
ORGANIZATION OF DATA/INFORMATION
Transaction#: 55643Date: 12/5/10Time: 4:08 pmMerchant: VitalesCard type: Master CardIssuer: First Bank
Transaction#: 55644Date: 12/6/10Time: 4:10 pmMerchant: WIU UnionCard type: Master CardIssuer: First Bank
Observations about these two “units” of data?
15
TRADITIONAL CONCEPT OF A FILE
CBT QUALITY MANAGEMENT COMMITTEEMeeting Minutes
Meeting Date/time: December 2nd, 2:00 p.m.Present: Larry Wall, Ken Nimrick, Xiang Yi,
Western Illinois University strives to maintain a community which values academic excellence; institutional integrity; and justice, equity, and diversity. Such an environment is essential in fostering the intellectual growth and personal development of all students. Each member of the University community shares responsibility in maintaining conditions which support the University's purpose. The Code of Student Conduct is designed to provide basic guidelines to advance the University's mission as a premier educational institution.
16
Transaction
ID
Transaction
Date
Transaction
Time
Merchant
55643 12/05/09 4:08 pm Vitales
55644 12/05/09 4:10 pm WIU Union
CONCEPT OF A DATABASE FILE
17
DEFINITIONS
18
Primary key
Record
attr. values
Attributes/field namesStructure/schema
DATABASE ORGANIZATION
PROD# DESCR. PRICE QUANTITY
IR888E Refrigerator $1,800 20
TS3233 Television $67 32
Record
19
Database – A group of related filesFile/table – A group of related recordsRecord – a grouping of related field valuesAttribute – property e.g. hair color
Schema -- This is the logical view of the database (tables and fields)Primary key – An attribute whose values are unique within a fileSecondary key – Any other attributeDBMS – software program to provide controlled data access
Database
Files/tables
Records
Attr. values
DATABASE ORGANIZATION
20
DATA MODELS AND
DBMS MODELS
21
Organization
Entity classes
Data model
File 2
File 1
Data base
cust.cust.
emp.emp.
22
DATA MODELS
Abstract view of the data & relationships
Captures data needs
Supports implementation
Relationship between students and courses?
between doctors and patients?
between teams and players?
23
DEFINITIONSEntity – Individual example of person, place or thing.Entity Class – Collection of related entities.Attributes – Properties of entity classes about which we would like to collect information.
24
DATA MODELS…
Three types of relationships among entity classes
A B1:1
A B1:M
A BM:N
For each value of A, oneand only one value of Band vice versa.
For each value of A, many values of B, but for each B only one A.
For each value of A, many values of B and vice versa.
25
DISCUSSION
Identify the types of the following relationships
Company -- president Instructor -- students Flights -- pilots City -- convention centers Club -- members Team -- players Company -- city Books – authors Artists -- records
26
DBMS ACTIVITIES
27
DBMS ACTIVITIES & FUNCTIONS
Activities with DBMS
Define structure/schema
Enter data
modify data
query data
get reports
28
Define structure/schema
DBMS ACTIVITIES & FUNCTIONS
Field Name Data type Description Length Decimals
Prod# Numeric Unique prod code
6 0
Descr Text Short prod
description
25 0
Price Currency Product price 6 2
This is called data definition
29
Enter data -- Create a data entry form
PRODUCT DATA ENTRY
Product #:
Description:
LabelField
Heading
Data entry form
DBMS ACTIVITIES & FUNCTIONS
30
DBMS ACTIVITIES & FUNCTIONS
AddDeleteChange
Modify data
Records/field values
31
DBMS ACTIVITIES..Database Retrieval
32
Query data – can use QBE or SQLlist products costing more than $2,000
Query by example (QBE) form
DBMS ACTIVITIES & FUNCTIONS
Prod# Descr. Price Quantity
> 2,000
33
DATABASE RETRIEVAL
THE STRUCTURED QUERY LANGUAGE
Each SELECT statement has three parts SELECT, FROM and WHERE
SELECT is used to select output attributes FROM is used to specify the tables WHERE is used for row selection criteria
SELECT <attr. list>FROM <tables>WHERE <condition1, condition 2…>
34
Flt# Pname Confirm#
AA1802 Smith PA5R2
PA802 Smith LX5R2
UA3702 Mahoney ZB46A
Select Flt#, Confirm#From ReservationWhere Pname = “Smith”;
Reservation
DATABASE RETRIEVAL..
SQL QUERY RESULTFlt# Confirm#AA1802 PA5R2PA802 LX5R2
35
SELECT Flt#, Deptime, ArrtimeFROM ??WHERE Depcity = "PHX" and Destcity = "ORD";
Flt # Depcity Destcity Deptime Arrtime
AA 802 PHX ORD 1:51 AM 6:05AM
UA 3702 COS D 7:35 AM 8:05 AM
AA 812 PHX SEA 4:55 AM 9:00 AM
D 42 PHX ORD 5:40 PM 9:15PM
FLIGHTS
ANOTHER EXAMPLE
What is the result of the query?
36
DISCUSSION
Write SQL queries to list:1) employee names.2) Employees who live in Macomb.3) employees who enjoy soccer.
EID E_name E_addr. E_city
423 Smith 100 Oak lane Macomb
425 Smith 100 Oak lane Macomb
501 Johnson 1430 N. Park street Rock Island
EMP.
37
THE THEORY OF RETRIEVAL
DEPTS.
EMPLOYEES
have
EID E_name E_addr.
11893 Jon 100 Oak street
11895 Carey 15 Candy lane
11896 Ross 1317 Fox creek
D_code D_name D_mgr
Fin. Finance Jon
Sas Sales and service Ross
Acc. Accounts Jan
Emp. file
Dept. file
38
SELECT table1.attr1, table2.attr2 . . . .
FROM table1, table2, . . . . .
WHERE table1.fkey = table2.fkey AND/OR
condition1 AND/OR
. . . . . . . . . . . . . ;
MULTI-TABLE SELECT STATEMENT
NOTE When there are multiple tables, attr. names preceded by table name The values of common attr. need to be equal in the WHERE part There can be more than one condition, connected by AND or OR
39
RH
PH
Detail
FieldsPF
RF
PRODUCT LISTING
PRODUCT # DESCR. PRICE
Product # Descr. Price
Average Price
Title
Column
Headings
Footer
A report specification
40
GETTING DATA OUT..
PRODUCT LISTING
PROD# DESCRIPTION PRICE
M100 Chair $ 50.00 M150 Table $200.00
Average Price $153.00
A generated report
41
Define structure /schema Enter data modify data query data get reports
Activities with DBMS
42
DBMS ORGANIZATION
D B M S Kernel
D B M S Kernel
Major Components of DBMS
Export/Import
Data Defn.Data Defn. SQLSQL
Prog. Language Interface
Prog. Language Interface
DataDiction-
ary
DataDiction-
ary
Screen/ReportGen.
Screen/ReportGen.
Appln.Gen.
Appln.Gen.
43
DBMS COMPONENTS..Data definition – the facility through which schema is defined. (how new tables are created).SQL interface – the facility through which SQL commands are typed in.Programming language interface – the facility which processes SQL commands embedded in application program. Also known
as the host language interface. Data dictionary – the facility that records details about the schema, reports, data entry forms etc.Screen & reports- the facility through which data entry screens and reports are created.Appln. Generation- the facility through which applications are created.Export/Import -- the facility through which files can be imported/exported in different DBMS formats.DBMS Kernel -- the actual programs which interact with the O/S and carry out data I/O.
44
45
USEFULNESS OF DATABASES
46
Suppose we have detailed information on each and every transaction in a store, what can we do with that?
What if a customer wants to return a shirt purchased in the store?
What if a manager wants to know what products were sold on a particular day?
USAGE OF DATA/INFORMATION
47
To store and record information e.g. bal, price, grades etc. To retrieve information e.g. check#432 cashed? To report information e.g. daily sales To answer queries e.g. how many shoes were sold?
IMPORTANCE OF DBMS’s
Databases are used:
To analyze trends Identify sales prospects
Advanced uses:
48
THAT’S ALL FOLKS!