D ATABASE Dr. Satria Mandala

R ELATIONAL D ATABASE F UNDAMENTALS What Is a Database? a database is any collection of data items (simple definition) a self-describing collection of integrated records that includes programming languages such as SQL (details definition) A database consists of both data and metadata.

D ATABASE M ANAGEMENT S YSTEM What Is a Database Management System? Block diagram of a DBMS based information system

D ATABASE M ODELS Hierarchical: These databases arrange their data in a simple hierarchical structure that allows fast access. Network: Network databases have minimal redundancy but pay for that advantage with structural complexity. Relational: These databases store their data in tables that are related to each other.

W HY RELATIONAL D ATABASE MODEL BETTER THAN BOTH HIERARCHICAL AND NETWORK MODELS ? A. The database structure of both hierarchical and network models are hard-coded into the application. That application is dependent on the specific physical implementation of the database. B. Relational databases offer structural flexibility; applications written for those databases are easier to maintain than similar applications written for hierarchical or network databases.

C OMPONENTS OF A RELATIONAL DATABASE

T ABLE

FORM

Query Design in Microsoft Access Result of Running the Query Command Q UERIES

R EPORTS

M ACROS

M ODULES

SQL F UNDAMENTALS What is SQL? What is Query? SELECT * FROM EMPLOYEE WHERE Age > 40 OR Salary > ;

SQL S TATEMENTS The SQL command language consists of a limited number of statements that perform three functions of data handling: Some of them define data, some manipulate data, and others control data.

SQL S TATEMENTS

R ESERVED W ORDS RESERVED WORDS are words that cannot be used for the name of any table or any function because have been reserved for special purpose in RDBMS There are several words have been reserved by SQL, for examples: SELECT, FROM, WHERE

D ATA T YPES Numerics Binary Strings Booleans Datetimes Intervals XML