Download Deck - Stefano Grazioli

Databases
Stefano Grazioli
© Stefano Grazioli - Ask for permission for using/quoting: [email protected]
Debriefing

Still doing well

Timing your posts

Easy meter
You do the talking

Name, major

Learning objectives

Things you like about the class

Things that can be improved

Strengths / Attitude towards the Tournament
Databases
Stefano Grazioli
© Stefano Grazioli - Ask for permission for using/quoting: [email protected]
Why do we need Databases?
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Program (e.g., VBA) data is volatile
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Data in one place for everyone to use
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Indispensable in commerce
DBs vs. DBMSs
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A database (DB) is an organized collection of data
A DataBase Management System (DBMS) is a software that
provides data-related functionality
User location
User or
User or
program
‘Client’
program
program
Data center
DBMS
DBMS: Access, Oracle, IBM DB2, SQL Server, MySQL...
DBs and the Web
User location
User or
User or
program
Browser
program
program
Data center
Web
server
DBMS
Relational DBMS
When a DBMS organizes your data so that they
appear to the users as TABLES, that DBMS is a
Relational DBMS, or RDBMS.
I speak
SQL
Client
program
I speak
SQL
RDBMS
WINIT
What Is New
In Technology?
© Stefano Grazioli - Ask for permission for using/quoting: [email protected]
Congratulations!
You are hired at SmallBank
Homework
© Stefano Grazioli - Ask for permission for using/quoting: [email protected]
You are a Business Intelligence
analyst at SmallBank
Welcome! So glad that you are here and can help us with Business
Intelligence! I have so many business questions for you…
(1) Who are our customers in Austin, TX? I need a list of first names,
last names and IDs
(2) What are the rates that we offered on our loans? Prepare a report
with the loan IDs and rates for the loans under $50,000,000
(3) ….
Please access our MS SQL Server and create these reports for me…
Accessing Business Data
User location
SQL Client
Visual Studio
Sql queries
Data center
RDBMS
MS SQL Server
F-sg6m-s4
SmallBank data:
Loan, Loan
Officer, Customer,
Insurance Plan
A file on the server
Example Table: Loan Officer
ACTUAL TABLE
DIAGRAM
LO id
f name
l name
phone
demo
Small Bank DB: Data Dictionary

Loan
l_id = the loan unique id
principal, rate, date_due,

Loan officer
lo_id = the loan officer’s unique id
f_name, l_name, phone

Customer
c_id = the customer’s unique id
f_name, l_name, city, state

Insurance plan
coverage = maximum amount covered
premium = amount to pay every year
Reading the Data Model
Primary key: a
unique identifier
used to retrieve the
record
Reading the Relationships
1
6
“A loan officer has
many loans, a loan
has one loan officer”
One
5
Many
2
3
4
SQL Queries
© Stefano Grazioli - Ask for permission for using/quoting: [email protected]
SQL

Structured Query Language
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The standard language for databases
70s:

- Codd
- SEQUEL – Structured English QUEry Language

commercialized it in 1979

1986 ISO/ANSI

Sometimes sought as a required skill in interviews
SQL EXAMPLE: A QUERY
SELECT First_Name, Last_Name, ssn
FROM StudentTbl
WHERE gpa > 3.0
ORDER BY Last_Name;
4+2 BASIC SQL COMMANDS
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SELECT = ‘search’
INSERT a new row
UPDATE a existing row
DELETE a row
CREATE a table
DROP a table
Navigating the Relationships (‘join’)
FK
foreign key: a PK in
another table, used
to link the two tables
FK
FK
FK
FK
Joins are commonsense
If I give you c_id
‘4977’, can you give
me the phone
numbers of the loan
officers for that client?
SQL Query
Select loan_officer.phone
from customer_in_loan, loan, loan_officer
where
customer_in_loan.c_id = '4977' and
customer_in_loan.l_id = loan.l_id and
loan.lo_id = loan_officer.lo_id
If I give you c_id ‘4977’, can
you give me the phone
numbers of the loan officers
for that client?