Types of Databases

When it comes to databases, there are various types to choose from depending on the specific needs of your application. The three commonly used types of databases are: relational databases, non-relational databases, and graph databases.

Relational Databases

Relational databases are based on the relational model, which organizes data into tables with rows and columns. They use structured query language (SQL) to define and manipulate the data. Relational databases are known for their ability to establish relationships between different tables and ensure data integrity through constraints and normalization.

MySQL, PostgreSQL, and Oracle are some popular examples of relational databases.

Non-relational Databases

Non-relational databases, also known as NoSQL databases, provide a flexible and scalable way to store and retrieve data. Unlike relational databases, they do not use a fixed schema and can handle unstructured and semi-structured data. NoSQL databases use different data models like key-value, document, columnar, and graph.

MongoDB, Cassandra, and Redis are examples of popular non-relational databases.

Graph Databases

Graph databases are designed to represent complex relationships between data entities. They use graph structures with nodes, edges, and properties to store and query data. Graph databases are ideal for scenarios that involve highly interconnected data and complex queries that require traversing relationships.

Neo4j and Amazon Neptune are examples of graph databases.

Understanding the different types of databases enables you to choose the most suitable one based on your application's requirements and scalability needs.

1// Example of creating a table in a relational database
2const mysql = require('mysql2');
3
4// Create a connection
5const connection = mysql.createConnection({
6  host: 'localhost',
7  user: 'root',
8  password: 'password',
9  database: 'mydatabase'
10});
11
12// Create a table
13const createTableQuery = `
14  CREATE TABLE customers (
15    id INT AUTO_INCREMENT PRIMARY KEY,
16    name VARCHAR(255),
17    email VARCHAR(255)
18  )`
19
20connection.query(createTableQuery, (error, results) => {
21  if (error) {
22    console.error('Error creating table', error);
23  } else {
24    console.log('Table created successfully');
25  }
26});