Overview
A database is an organized collection of data that can be centralized and used to separate the data to be handled by an application from the code. Applications can do data modification like insert or update correctly and safely by using a database.
There are different types of databases depending on their structure and purpose of use, such as Relational Databases (RDB) and Non-Relational Databases known as NoSQL. The most commonly used type of database is the relational database. A relational database manages data in a collection of tables. A table has multiple columns for each type of data and various constraints such as primary keys and foreign keys that are set before use. The database structure and constraints are very important parts that affect the performance of the entire system.
To communicate with a database in a web application, it is necessary to write the code to operate the database in the program. For example, in a relational database, you can insert, select, update, and delete data (CRUD operations) by including a special language known as SQL in the code.
Learning Objectives
By learning about databases, you will be able to properly manage the data in your web applications.
The amount of data handled by web applications are enormous, such as user data from membership registration and product data from e-commerce sites. By using a database, it's possible to store all the related data at once and quickly search for and retrieve the desired data.
In addition, by upholding data integrity and preventing data redundancy, the database can prevent data loss and duplication due to simultaneous use by multiple users and maintain consistency. Data encryption can be applied to improve security, and backup functions ensure data integrity.
With the recent web application frameworks, it's possible to implement them with an O/R mapper without directly using SQL. However, since SQL is running inside this mapper, it will be necessary to learn SQL to achieve efficient data access.
Learn about databases in order to create full-fledged services.
Learn from Here
A good place to start learning about databases is with relational databases, which are widely used today. First, let's learn about SQL to manipulate relational databases.
Getting Data from SQL
Understand Types and Purposes of Databases
Get Data using SELECT
Use WHERE to Get Specific Data
Data Sorting
Use Aggregate Functions
Group the Data
Create a Subquery
Join Multiple Tables with JOIN
Analyze the Database of a Fashion Website
Modifying Data in SQL
Add Data with INSERT
Update Data with UPDATE
Delete Data with DELETE
Recommended Materials
SQL Study I | Progate
You can learn the basic syntax of SQL in an easy-to-understand manner while actually working with it. Progate is a good place to start as it has a lot of content.
![SQL Study I | Progate]()
SQL Study I | Progate
Progate is an online platform to learn programming. Learn to build your own apps and services.
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