1. Advanced Accounting Information Systems
Day 11
Understanding the SQL Language
September 18, 2009

2. Announcements Assignment 2 due Monday
Business Week activities continue

3. Catch up on topics we skipped
Database structures
Ways to organize individual records in a database
Hierarchical
Network
Relational

4. Catch up on topics we skipped
Data warehouse
Identify similarities between data warehouse and a fine restaurant (p )

5. Objectives – Chapter 6 – Understanding the SQL Language
Basic SQL features and functions
SELECT statement fundamentals
Operators and functions
DDL and DML statements

6. Questions for today
Five basic features of SELECT

7. SQL Structure
DDL
DML and DQL

8. SQL Structure SQL developed in 1980s incorporates both DDL and DML
standard per ANSI and ISO
Included in many mainstream DBMS
DB2
Oracle
MySQL
Informix
Microsoft SQL Server

9. SQL Structure Basic features DDL DML Command operators Functions
Transaction control

10. SQL Structure Two basic options for executing SQL commands
Interactive (or dynamic)
Embedded
Query mode

11. Interactive SQL Character based interface (see Figure 6.1)
Menu-driven interface (see Figure 6.2)

12. Embedded SQL
Best suited to activities that must be performed periodically
SQL commands are part of an executable program
Can also be used in application programs

13. Command Basics Command syntax Command keywords (command clauses)
Command parameters
Results set (relational set)
SELECT
FROM
WHERE

14. Error messages Command did not complete successfully
Why do errors return give so little information?

15. SELECT fundamentals
DBMS analyzes the declarative SQL SELECT statement and creates an access path – plan for what steps to take to respond to the query
SELECT
FROM
WHERE ;

16. Using SELECT to evaluate expressions
Select total_value

17. Understanding Operators and Functions
Unary operators
Binary operators
Arithmetic operators
Comparison and logical operators

18. DDL
Create

19. DML INSERT into TABLENAME VALUES
Insert into INVOICE (INVNO, INVDATE, AMOUNT) VALUES
(324, 5/25/09, 13.30)

20. DML UPDATE TABLE SET COLUMN-NAME =
UPDATE INVOICE SET AMOUNT = WHERE INVNO = 325;

21. DML DELETE FROM TABLENAME WHERE SEARCH-CONDITION DELETE FROM INVOICE
WHERE INVNO = 800

22. DQL SELECT LIST ATTRIBUTES FROM TABLE WHERE QUALIFYING CONDITIONS
GROUP BY
ORDER BY
WHAT IS THE OTHER NAME FOR QUALIFYING CONDITIONS?
USE * TO retrieve entire record in one table
Retrieving other values
Expression
Function

23. Questions for Monday
What is the difference between comparison and logical operators?
Identify and describe the use of the three basic DML commands