Introduction to Database - Learn Data Science

Database is an organized collection of structure data or information that is stored in such a way that it can be easily accessed , create, update, delete and managed.

Table of Contents

Data

Data are raw fact that have no specific meaning.

Information

Information is processed data that has purpose and meaning.

Data Processing

Data is a collection of facts & figures, such as values or measurements. The data is the raw material to be processed by a computer.

Data are manipulated to produce output. When this output can be used to help people make decisions, it is called information.

Data processing is defined as series of actions or operations that convert data into useful information.

Data processing also refers to the complete check of the data validity, accuracy, consistence, integrity and its relevance to the client’s requirements.

Input

Inputis the task where data is coded or converted into machine readable form so that it can be processed through a computer.

Processing

Data processing refers to the collection and manipulation of data to produce meaningful information. It is the process of manipulation data to generate required information. Different method and techniques are used to process the data data.

classifying,
sorting,
calculating,
summarizing,
comparing

Output

Outputis presented to users in various report formats like printed report, audio, video, or on monitor.

Storage

Storage is used to store information for future use and reporting

Database Terminology

Column or Field
Row or Record
Table (similar to an Excel Worksheet)
Primary Key –unique and mandatory
Foreign Key –a cross-reference between tables because it references the primary key of another table
Relationship–created though foreign keys.
Database relation can be :
- One to one (1-1)
- One to many (1-M)
- Many to One (M-1)
- Many to Many (M-M)

Field , Record and Table

Table

A set of data arranged in a columns and rows. The column represent characteristics/properties of stored data and the row represent the actual data entries.

E_ID	E_NAME	E_SALARY
1	RAM	60000
2	SHYAM	45000
3	SITA	56000
4	GITA	70000
5	HARI	80000

Field

Fields are columns in a table with specific information about the data.

In above table e_id, e_name and and e_salary are fields that provides the information about id, name and salary of different employees.

Record

Record is a individual entry that exists in a table. It is also known as row.

Records give the complete information of a single entry or entity.

E_ID	E_NAME	E_SALARY
1	RAM	60000
2	SHYAM	45000
3	SITA	56000
4	GITA	70000
5	HARI	80000

In above table selected row gives the complete information of about the particular employee sita.

What is Database ?

Database is an organized collection of structure data or information that is stored in such a way that it can be easily accessed , create, update, delete and managed.

A database is usually controlled by a database Management System (DBMS)

In Database, data are organized in row and columns in the form of table.

Most database use structure query language (SQL) for writing and querying data.

SQL , MYSQL, Oracle, Postgresql are the example of database.

What is database mangement System (DBMS)

Database management system (DBMS) is a type of software or tools that helps to manage the database. User can create , maintain, manipulate and retrieve data or information from a single table or group of interrelated table.

DBMS act as an interface between user/application program and database.

dbms , database — *Figure : DBMS act as interface between user and Database*

Example : Oracle Database , SQL Server, MS-access, Mysql Dbase etc. are used to managed data in DBMS.

DBMS application are Student information system, hospital management system ,Library Management System, customer relationship Management system.

Objectives of the DBMS

To store mass storage of relevant data.
To Make the data access easy for the user.
To eliminate the data redundancy.
To Make the latest modification to the database available immediately
Allow for multiple user to be active at one time ( Data can be accessed concurrently)
The advancement in the database enables to add more data and program to the system
To protect the data from physical harm and unauthorized access.
To Maintain Data confidentiality.