SQL is a really useful language, but exactly what is it, and what is it used for?
If you don’t know, then great news – you’ll quickly learn just what SQL is and what you can use it for!
What Is SQL?
SQL stands for Structured Query Language. It is a computer language that allows you to create, modify and query databases.
It was developed by IBM in the 1970s as an alternative to programming languages like COBOL or PL/1. The original version of SQL was called SQLLite, which was later renamed SQL.
The first version of SQL was released in 1977 and since then many other versions have been created such as SQL Server, MySQL, and PostgreSQL. Today, there are more than 20 million developers using SQL every day.
In this article, we will cover what SQL is, how it works, its advantages and disadvantages, and more!
How Does SQL Work?
SQL is a declarative language – meaning that it tells the database what data you want instead of telling it how to get it.
This makes it much easier to use because you don’t need to worry about how to structure your code. You just tell the database what you want and let it figure out everything else.
For example, if you wanted to find all customers who live in California, you would simply ask the database: “Find me all customers living in California”.
The database will understand exactly what you mean and return all records matching your request.
If you were to do something similar in another programming language, you’d probably need to write a lot of code to achieve the same results.
For example, you could write a program to loop through each customer record and check whether they lived in California or not. If so, add their name to a list. However, this approach isn’t very efficient because you’re wasting time on unnecessary tasks.
With SQL, you only need to specify what you want.
The database itself handles everything else. So, when you execute a SQL statement, the database performs all the necessary steps to retrieve the data specified in the query.
What Is SQL Used For?
SQL is mainly used to store data in databases. A database stores information in tables where each table has columns and rows.
Each row represents one record while each column represents a value stored in that particular row.
For example, if you want to store the names of all students in a class, you would need two tables: Students and Classes. In the Students table, you would add a column named StudentName, and in the Classes table, you would add a column ClassName.
You can use these tables to find out the name of all students who belong to a certain class. To do so, you would run a query on the classes table with a condition that checks whether the student belongs to that class. If yes, you would return the name of that student.
This is just one example of how you could use SQL to store and retrieve data from a database.
What Is A Database?
A database is a collection of structured data. In simple terms, a database is a collection of records where each record contains fields and values.
These fields may contain text, numbers, dates, times, images, videos, audio files, links, and much more.
There are different types of databases, including relational databases, object-oriented databases, document-oriented databases, and graph databases.
Advantages Of SQL
There are several reasons why people choose to use SQL over other programming languages. Here are some of them:
It’s Easy To Learn
SQL is very similar to English. As long as you know basic English grammar, you can easily understand how SQL works.
You don’t need any special skills – unlike most programming languages, you don’t need to know how to program before learning SQL.
One of the biggest benefits of using SQL is that it’s extremely reliable. Unlike other types of programs, SQL won’t crash or freeze during execution.
Even if the server crashes, the database will still continue running.
Another benefit of using SQL is that you’ll save lots of time compared to manually coding a solution.
You Can Use SQL Anywhere
SQL is not tied to any specific platform. You can use SQL on Windows, Linux, Mac OS X, and even mobile devices.
Disadvantages Of SQL
Although SQL is a powerful tool, it also comes with some limitations. Some main ones include:
It’ll Take Time To Master
Learning SQL takes time because it requires a lot of practice. However, once you get the hang of it, you won’t regret spending that much time learning it.
There Are Lots Of Different Types Of SQL
There are hundreds of different types of SQL. Some of them are very simple while others are extremely complex. Knowing all of them is impossible but knowing at least the basics is enough to build a working application.
Here are some of the most commonly used SQL queries:
Select statement returns only one result set. It lets you select one or multiple records from a table based on conditions.
For example, let’s say you wanted to find out the name and age of all students in a certain class. You would run a SELECT statement with a WHERE clause that checks whether the student’s name matches the name of the class.
An update statement allows you to change values in a table.
For example, you might want to increase the salary of every employee by $1000. You would first create an UPDATE statement that contains the new salary amount. Then you would run the statement using the INSERT INTO command.
Insert statement adds new rows to a table. The difference between insert and update statements is that insert doesn’t affect existing data whereas update does.
Delete statement removes rows from a table. Unlike delete statements in other programming languages, there is no way to remove more than one row at a time.
So if you have 1000 rows in your table, you will need to loop through all of them and check whether they match the condition specified in the WHERE clause.
Join statement combines results from two or more tables. For example, if we had two tables: Students and Courses, then we could combine their contents using a join statement.
What Are The Biggest Uses Of SQL Today?
SQL has become so popular that it’s now being used in many industries including finance, banking, healthcare, government, retail, manufacturing, education, insurance, etc.
In fact, almost half of Fortune 500 companies rely heavily on SQL databases. Here are just a few examples of where SQL is being used:
Banks use SQL to store information about customers’ transactions such as deposits, withdrawals, payments, etc.
Healthcare organizations use SQL to store patient medical information. They also use SQL to manage billing systems and inventory management.
Government agencies use SQL to store information related to taxes, budgets, public safety, etc.
Retailers use SQL to keep track of customer orders, inventory, sales, etc.
Manufacturers use SQL to track production schedules, quality control, etc.
Education institutions use SQL to store grades, attendance, assignments, etc.
SQL is a valuable software tool – and one that’s well worth learning! Hopefully, this article has helped you to learn what SQL is, and just how it can be used.