les00 intoduction
TRANSCRIPT
Copyright Oracle Corporation, 1998 All rights reserved
I
Introduction
I-2 Copyright Oracle Corporation, 1998 All rights reserved
Objectives
After completing this lesson, you should be able to do the following
• Discuss the theoretical and physical aspects of a relational database
• Describe the Oracle implementation of the RDBMS and ORDBMS
• Describe how SQL and PL SQL are used in the Oracle product set
• Describe the use and benefits of PL SQL
I-3 Copyright Oracle Corporation, 1998 All rights reserved
System Development Life Cycle
Strategy
and
AnalysisDesign
Build
and
Document
Transition
Production
I-5 Copyright Oracle Corporation, 1998 All rights reserved
Data Storage on Different Media
Electronic
spreadsheetFiling cabinet
Database
SALGRADE
GRADE LOSAL HISAL
--------- --------- ---------
1 700 1200
2 1201 1400
3 1401 2000
4 2001 3000
5 3001 9999
DEPT
DEPTNO DNAME LOC
--------- -------------- ----------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
I-6 Copyright Oracle Corporation, 1998 All rights reserved
Relational Database Concept
• Dr E F Codd proposed the relational model for database systems in 1970
• It is the basis for the relational database management system RDBMS
• The relational model consists of the following
– Collection of objects or relations
– Set of operators to act on the relations
– Data integrity for accuracy and consistency
I-7 Copyright Oracle Corporation, 1998 All rights reserved
Definition of a
Relational DatabaseA relational database is a collection of relations or two-dimensional tables
Database
DEPTNO DNAME LOC
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
Table Name DEPT
EMPNO ENAME JOB DEPTNO
7839 KING PRESIDENT 10
7698 BLAKE MANAGER 30
7782 CLARK MANAGER 10
7566 JONES MANAGER 20
Table Name EMP
I-8 Copyright Oracle Corporation, 1998 All rights reserved
Data Models
Model of
system
in client’s
mind
Entity model of
client’s model
Table model
of entity model
Tables on disk
Server
I-9 Copyright Oracle Corporation, 1998 All rights reserved
• Create an entity relationship diagram from business specifications or narratives
• Scenario
– “ Assign one or more employees to a department ”
– “ Some departments do not yet have assigned employees ”
Entity Relationship Model
EMPLOYEE
# number
name
o job title
DEPARTMENT
# number
name
o location
assigned to
composed of
I-10 Copyright Oracle Corporation, 1998 All rights reserved
Entity Relationship
Modeling ConventionsEntity
Soft box
Singular, unique name
Uppercase
Synonym in parentheses
Attribute
Singular name
Lowercase
Mandatory marked with “ ”
Optional marked with “o”
Unique Identifier UID
Primary marked with “#”
Secondary marked with “ # ”
EMPLOYEE
# number
name
o job title
DEPARTMENT
# number
name
o location
assigned to
composed of
I-12 Copyright Oracle Corporation, 1998 All rights reserved
Relational Database Terminology
1
2 3 4
5
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
------------- ------------ --------------------- -------- ---------------- ----------- --------------
7839 KING PRESIDENT 17-NOV-81 5000 10
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7900 JAMES CLERK 7698 03-DEC-81 950 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7369 SMITH CLERK 7902 17-DEC-80 800 20
7788 SCOTT ANALYST 7566 09-DEC-82 3000 20
7876 ADAMS CLERK 7788 12-JAN-83 1100 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
6
I-13 Copyright Oracle Corporation, 1998 All rights reserved
Relating Multiple Tables
• Each row of data in a table is uniquely identified by a primary key PK
Table Name EMP Table Name DEPT
Primary key Primary key
• You can logically relate data from multiple tables using foreign keys FK
Foreign key
EMPNO ENAME JOB DEPTNO
7839 KING PRESIDENT 10
7698 BLAKE MANAGER 30
7782 CLARK MANAGER 10
7566 JONES MANAGER 20
DEPTNO DNAME LOC
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
I-14 Copyright Oracle Corporation, 1998 All rights reserved
Relational Database Properties
A relational database
• Can be accessed and modified by executing structured query language SQL statements
• Contains a collection of tables with no physical pointers
• Uses a set of operators
I-15 Copyright Oracle Corporation, 1998 All rights reserved
Communicating with a RDBMS
Using SQL
Database
SQL> SELECT loc
2 FROM dept;
SQL statement
is entered Statement is sent to
database
LOC
-------------
NEW YORK
DALLAS
CHICAGO
BOSTON
Data is displayed
I-16 Copyright Oracle Corporation, 1998 All rights reserved
Relational Database
Management System
User tables Data
dictionary
Server
I-17 Copyright Oracle Corporation, 1998 All rights reserved
Oracle8 Object Relational
Database Management System
• User-defined data types and objects
• Fully compatible with relational database
• Support of multimedia and large objects
• High-quality database server features
I-18 Copyright Oracle Corporation, 1998 All rights reserved
Defining an Object
An object
• Is a person, place, or thing
• Knows things about itself and performs actions
• Has an identity
I am a clock I know
my time zone, and I
can display time
I-19 Copyright Oracle Corporation, 1998 All rights reserved
Using an Object Model
• Objects model a problem to solve
• The model is stated in terms of the interactions between objects
• Object models closely resemble the real world
Customers Business
Buy
Sell
I-20 Copyright Oracle Corporation, 1998 All rights reserved
Characteristics of Object Systems
• Present information in object form
• Classify objects into object types
• Inherit attributes and code
• Hide data, code, and attributes
• Interact with other objects
• Recognize different objects without analysis
• Interpret the same command in different ways
I-21 Copyright Oracle Corporation, 1998 All rights reserved
Oracle Complete Solution
SQL PL SQL
Oracle7/8
Applications
HR
Financials
ManufacturingOracle Designer
Oracle Developer
Data tables
Data
dictionaryDatabase
SQL Plus
Discoverer
I-22 Copyright Oracle Corporation, 1998 All rights reserved
SQL StatementsSELECT
INSERT
UPDATE
DELETE
CREATE
ALTER
DROP
RENAME
TRUNCATE
COMMIT
ROLLBACK
SAVEPOINT
GRANT
REVOKE
Data retrieval
Data manipulation language DML
Data definition language DDL
Transaction control
Data control language DCL
I-23 Copyright Oracle Corporation, 1998 All rights reserved
About PL SQL
• PL SQL is an extension to SQL with design features of programming languages
• Data manipulation and query statements of SQL are included within procedural units of code
I-24 Copyright Oracle Corporation, 1998 All rights reserved
PL SQL Environment
PL SQL
block
PL SQL engine
Oracle Server
Procedural
Statement
Executor
PL SQL
SQL
SQL Statement Executor
PL SQL
block
I-25 Copyright Oracle Corporation, 1998 All rights reserved
Tables Used in the Course
EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO
--------- ---------- --------- --------- --------- --------- --------- ---------
7839 KING PRESIDENT 17-NOV-81 5000 10
7698 BLAKE MANAGER 7839 01-MAY-81 2850 30
7782 CLARK MANAGER 7839 09-JUN-81 2450 10
7566 JONES MANAGER 7839 02-APR-81 2975 20
7654 MARTIN SALESMAN 7698 28-SEP-81 1250 1400 30
7499 ALLEN SALESMAN 7698 20-FEB-81 1600 300 30
7844 TURNER SALESMAN 7698 08-SEP-81 1500 0 30
7900 JAMES CLERK 7698 03-DEC-81 950 30
7521 WARD SALESMAN 7698 22-FEB-81 1250 500 30
7902 FORD ANALYST 7566 03-DEC-81 3000 20
7369 SMITH CLERK 7902 17-DEC-80 800 20
7788 SCOTT ANALYST 7566 09-DEC-82 3000 20
7876 ADAMS CLERK 7788 12-JAN-83 1100 20
7934 MILLER CLERK 7782 23-JAN-82 1300 10
EMP
DEPT
DEPTNO DNAME LOC
--------- -------------- ----------
10 ACCOUNTING NEW YORK
20 RESEARCH DALLAS
30 SALES CHICAGO
40 OPERATIONS BOSTON
GRADE LOSAL HISAL
--------- --------- ---------
1 700 1200
2 1201 1400
3 1401 2000
4 2001 3000
5 3001 9999
SALGRADE
I-26 Copyright Oracle Corporation, 1998 All rights reserved
Summary
• Relational databases are composed of relations, managed by relational operations, and governed by data integrity constraints
• The Oracle Server allows you to store and manage information by using the SQL language and PL SQL engine
• PL SQL is an extension to SQL with design features of programming languages