1. Databases
Stefano Grazioli

2. Debriefing
Still doing well
Timing your posts
Easy meter

3. You do the talking Name, major Learning objectives
Things you like about the class
Things that can be improved
Strengths / Attitude towards the Tournament

4. Databases
Stefano Grazioli

5. Why do we need Databases?
Program (e.g., VBA) data is volatile
Data in one place for everyone to use
Indispensable in commerce
Database

6. DBs vs. DBMSs DBMS DataBase DataBase file(s)
A database (DB) is an organized collection of data
A DataBase Management System (DBMS) is a software that provides data-related functionality
DataBase
User location
Data center
User or program
User or program
‘Client’ program
DBMS
DataBase file(s)
DBMS: Access, Oracle, IBM DB2, SQL Server, MySQL...

7. DBs and the Web DBMS DataBase DataBase file(s) Web server
User location
Data center
DataBase
User or program
Web server
User or program
Browser program
DataBase file(s)
DBMS

8. Relational DBMS RDBMS “tables inside”
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
“tables inside”
I speak SQL
RDBMS
Client program

9. What Is New In Technology?
WINIT
What Is New In Technology?

10. Congratulations! You are hired at SmallBank
Homework

11. 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…

12. Accessing Business Data
SmallBank data:
Loan, Loan Officer, Customer, Insurance Plan
User location
Data center
RDBMS MS SQL Server
SQL Client Visual Studio
Sql queries
F-sg6m-s4
A file on the server

13. Example Table: Loan Officer
ACTUAL TABLE DIAGRAM
LO id
f name
l name
phone
demo

14. 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

15. Reading the Data Model
Primary key: a unique identifier used to retrieve the record

16. Reading the Relationships1 6
“A loan officer has many loans, a loan has one loan officer”
One 5 2
Many 3 4

17. SQL Queries

18. SQL Structured Query Language 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

19. SQL EXAMPLE: A QUERY SELECT First_Name, Last_Name, ssn FROM StudentTbl
WHERE gpa > 3.0
ORDER BY Last_Name;

20. 4+2 BASIC SQL COMMANDS SELECT = ‘search’ INSERT a new row
UPDATE a existing row
DELETE a row
CREATE a table
DROP a table

21. Navigating the Relationships (‘join’)FK
foreign key: a PK in another table, used to link the two tables FK FK FK FK

22. Joins are commonsense
If I give you c_id ‘4977’, can you give me the phone numbers of the loan officers for that client?

23. 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?