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Welcome to SQL Basics, a blog series crafted for beginners. If you’re wondering what SQL is and how to use it, you’ve found the right place. SQL (Structured Query Language) is a standard programming language for managing data in databases. By the end of this guide, you’ll have a solid foundation in SQL.
What is SQL?
SQL, which stands for Structured Query Language, is a language that allows us to communicate with databases. Data scientists, back end developers, database administrators, among others, use this language for tasks like fetching, updating, and manipulating data.
Working with SQL
The beauty of SQL is in its simplicity. At a basic level, the following are some key tasks that we can achieve using SQL:
- Creating databases and tables.
- Inserting data into tables.
- Querying and retrieving data from a database.
- Updating and deleting data in a database.
Creating a Database
The first step in working with SQL is creating a database. This is achieved with the CREATE DATABASE command.
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CREATE DATABASE my_first_db; |
Creating a Table
Once our database is created, we can then create a table within the database using the CREATE TABLE command.
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CREATE TABLE Customers ( CustomerID int, CustomerName varchar(255), ContactName varchar(255), Country varchar(255), City varchar(255), PostalCode varchar(255) ); |
Inserting data into the Table
After creating a table, we can insert data into it using the SQL INSERT INTO command.
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INSERT INTO Customers (CustomerID, CustomerName, ContactName, Country, City, PostalCode) VALUES (1, 'John Doe', 'John Doe', 'USA', 'New York', '10001'); |
Querying Data
Querying data from a database is one of the most common operations in SQL. This is achieved with the SQL SELECT statement.
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SELECT * FROM Customers; |
The above command will help you retrieve all data from the ‘Customers’ table. If you would like to select only certain fields, you can specify them instead of using the ‘*’ symbol.
Summary
SQL is a powerful language for managing and manipulating data in databases. Although we’ve just scratched the surface, this introduction provides a solid base from which to explore more complex tasks and commands.
Stay tuned for more SQL Basics posts, where we will delve into updating data, deleting data, and more advanced queries.