Lecture 1 Concepts of Database and Relational Database

Lecture 1 Concepts of Database and Relational Database System 753 412 Database Management Master of Arts Program in Library and Information Science 1

Database Definition Field 1 Field 2 Stored Field 3 Sorted Record 1 Record 2 Record 3 Processing Shared Revised Retrieved Record. n Reported 4

Database Definition l any collection of data, or information, that is specially organized for rapid search and retrieval by a computer. (Encyclopaedia Britannica 2004 ) l specially organized : Stored l Sorted l Shared l Revised l Retrieved l Reported l 5

Advantages & Disadvantages of Database Advantages: • Data can be collected and shared • Reduce data duplication • Avoid conflict of data • Control data integrity • Data can be easily used Disadvantages: • Expensive • Risk of loss of data • Risk of unsecured • Risk of privacy and property interference 6

Types of Database • Bibliographic database • Non-bibliographic database • Full-text database • Multimedia database • Web database 7

Database System • Data • can integrated, can sharing • Hardware (Computer and peripheral( • Secondary Storage for database : HD • CPU, Primary Storage for compute : CPU, RAM • Software • DBMS : ORACLE, SQL, ACCESS • Peopleware • Users, Database Administrator (DBA), Programmer, Operator 8

Hierarchical Database Model Final Component 1 Part A Component 2 Part B Part F Part C Part D Part E Part G เปนฐานขอมลทจดลำดบความสำคญระหวางแฟมขอมลตามลำดบชน 10

Hierarchical Database Model Course Registration Student Faculty Staff Course data Course teach จดลำดบความสำคญระหวางแฟมขอมลตามลำดบชน 11

Network Database Model Student Faculty Staff Course Registration Student’s Advisor Faculty Staff Course Lecturer ฐานขอมลทมความสมพนธระหวางแฟมขอมลถงกนหมด 12

Relational Database Model Student Register Advise Faculty Staff Teach Course 13

Concepts of Relational Database System l ���������� ���� (Relation( l ������ l l ���������� �� ���������������������� (Database Specific Integrity Rule) l ����������� (General Integrity Rule) l l ���������� l One to one relation / One to many relation / Many to many relation 14

��������� (General Integrity Rule) Foreign key - FK Primary key - PK 19

RDBMS Concepts 3 : ��������� l. One to one relation l. One to many relation l. Many to many relation 21