For an instructor lead, in-depth look at learning SQL click below.
Structured Query Language, commonly known as SQL, is a standard language for managing and manipulating databases. Used extensively across various sectors, SQL skills are highly sought after in the job market. In our weekend crash course, you’ll gain a solid understanding of SQL essentials.
Why SQL?
The core rationale behind using SQL is its simplicity. It’s easy to learn due to its english language-like syntax, and it’s adept at managing and manipulating databases. Regardless of the size of the data sets – small or big – SQL easily handles data management tasks.
SQL Fundamentals
SQL Syntax
The basic syntax of SQL revolves around commands written in uppercase, followed by the object of the command, and where the action happens. It is quite simple and easy to understand. For instance:
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SELECT * FROM Employees |
In this example, SELECT is the command, * represents all columns and Employees is the object of the command, ie. the name of the table.
Creating a Database
The first step in working with SQL is setting up a database. Below is an example of how to create a database named “Company”.
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CREATE DATABASE Company; |
Creating a Table
Once the database is up, you’ll need to create tables. Here’s an example where we’re creating a table named “Employees” with a few basic fields:
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CREATE TABLE Employees ( ID int, Name varchar(255), Age int, Address varchar(255), Salary decimal(18, 2), ); |
Inserting Data into a Table
Now that we have a table, let’s add some data. Here’s an example of how to add data to the Employees table:
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INSERT INTO Employees (ID, Name, Age, Address, Salary) VALUES (1, 'John Doe', 30, '123 Elm Street', 50000.00); |
Query Data
One of SQL’s best features is the ability to fetch data based on particular conditions. The basic structure of an SQL query is:
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SELECT column1, column2 FROM table_name WHERE condition; |
To fetch all details of employees above 25 years old:
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SELECT * FROM Employees WHERE Age > 25; |
Summary
These are some of the basics of SQL. By learning these, you’ll have a good start to handle databases effectively. Remember, the best way to solidify these concepts is through consistent practice. Happy Learning!