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What is a Database?
Definition
A database is an organized collection of structured information, or data, typically stored electronically in a computer system. Databases are managed by Database Management Systems (DBMS).
Purpose
The main purpose of a database is to store and retrieve related information effectively. It allows users to perform various operations such as inserting, updating, deleting, and querying data.
Types of Databases
There are several types of databases, including relational databases, NoSQL databases, and cloud databases, each serving different purposes and use cases.
Relational Databases
Relational databases store data in tables with rows and columns. They use SQL (Structured Query Language) for defining and manipulating the data.
NoSQL Databases
NoSQL databases are designed to store unstructured data. They are more flexible than relational databases and can handle large volumes of data with high speed and scalability.
Cloud Databases
Cloud databases are databases that run on cloud computing platforms. They offer scalability, reliability, and accessibility from anywhere in the world.
-- Example of Creating a Table in SQL
CREATE TABLE Employees (
EmployeeID int,
FirstName varchar(255),
LastName varchar(255),
BirthDate date
);
SQL Commands
SQL commands are used to perform tasks such as updating data on a database, or retrieving data from a database. Some common SQL commands include SELECT, INSERT, UPDATE, DELETE, and CREATE.
Database Management Systems (DBMS)
DBMS is software that interacts with end users, applications, and the database itself to capture and analyze data. Examples include MySQL, PostgreSQL, MongoDB, and Oracle.
Data Integrity
Data integrity refers to the accuracy and consistency of data stored in a database. It is maintained through constraints, transactions, and error-checking mechanisms.
Data Security
Data security involves protecting data against unauthorized access or corruption. This is achieved through encryption, authentication, and access controls.
Backup and Recovery
Backup and recovery processes ensure that data is protected and can be restored in case of data loss due to system failures or disasters.
Scalability
Scalability refers to the ability of a database to handle increased loads without affecting performance. This is crucial for businesses experiencing growth.
Console Output:
Table 'Employees' created successfully.
