Database Concept

Definition and need of database:

Data is a collection of facts organized into useful information. For example the collection of students etc this data can be processed by the computer and converted into information. One of the major functions of a computer is to provide vast data storage.

   Database is a collection of information stored in a computer in a systematic way, such that a computer program can search through it and answer questions posed by the user. Database management involves storage and maintenance of a catalog of information in a database. Database Management System (DBMS) software is used to enable the user to enter, organize, select and query data in a database. It can also be thought of as an electronic filing system. Some examples of common DBMS are Microsoft Access, Oracle, Sybase, M.S. SQL server and Informix. The next section describes the basic concepts of database.

Database and Tables

A database is a collection of related data organized and stored in the form of tables consisting of rows and columns. The rows in a database table are called records and the columns are called fields. For example a college maintains a database consisting of student details and another database consisting of the faculty details. When students take admission to the college or when a new faculty to joins the college, the database is updated. Faculty is allocated to students and classes for teaching. In both these cases the information in the database dose not over lap but is linked together.

      A database contains many tables and each table contains a set of related data. A typical financial database can contains tables for accounts payable, customer records, accounts receivable, vendor, and employee records and payroll details. The separate tables are used to eliminate redundant data. Some keyword involved with databases Data-Type and Value. Here is the hierarchy that any DBMS uses in breaking down a database.