Ever find yourself asking, ‘what is SQL’? We’ve got you covered. Put simply, SQL is a language that is used to manage data that’s held in a relational database management system. It uses tables to both manipulate and retrieve information from databases for analysis.
As an early coder, you’ll have likely heard the acronym SQL among your peers, colleagues or teachers. However, if you want to get to grips with database management, SQL is certainly something you will need to learn – and we’re here to help you get started.
What does SQL stand for?
Good question! SQL stands for Structured Query Language. Initially, the name of the language was meant to be Sequel (Structured English Query Language). However, due to copyright, the name was shortened to SQL.
What is SQL?
What is structured query language, you ask? SQL is the set of instructions used to interact with databases. It allows users to create, retrieve, update, and delete data. Of course, this is a straightforward definition for such a complex subject. Let’s go a little deeper.
- SQL is a special-purpose programming language designed for managing data stored in a relational database management system.
- SQL is the language with which a coder communicates with a database to manipulate its data.
- It is their guiding hand, voice, and fingertips dragging across a screen, helping the coder navigate and organise the data as they see fit.
- It is how a coder converses with the machine.
What is SQL used for?
SQL is used for database architecture and management – making it a vital tool for anyone who wishes to pursue a career as a database administrator.
For those unfamiliar with programming languages and website architecture, the work of SQL will often go unnoticed. Still, those who have seen behind the curtain will know it as one of the fundamental building blocks of modern database architecture.
Why is SQL important?
SQL provides a standardised method for interacting with databases, making it possible for users to work with different database systems regardless of the vendor. Additionally, SQL is widely used in data analytics and business intelligence applications, as it enables users to extract meaningful insights from large datasets. Invented in the 1970s, SQL has since become one of the most widely used programming languages for managing and querying databases.
- Data retrieval: SQL can be used to retrieve specific information from a database based on certain criteria.
- Data Modification: Developers can use SQL to insert new records, update existing information, and even to delete information from a database.
- Data Management: SQL can help manage the structure of a database. It can create tables, define relationships between tables, and set constraints to ensure data integrity.
- Data Analysis: SQL is used to analyse data. It can aggregate data, calculate statistics, and generate reports.
- Data Integration: You can use SQL to combine data from different sources into a single dataset.
Data Security: SQL is used to manage user permissions and access controls. It can define user roles and grant or revoke access to specific parts of a database.
Benefits of using SQL
Originally designed at IBM in the early 1970s, SQL is still just as strong as it was back then – its ability to adapt and evolve makes it uncomplicated and easy to use. Sure, it may be one of the oldest languages, but SQL has still got ‘it’.
Where so many programming languages have failed to adapt over time, SQL has cemented its place as the backbone of data architecture. Want to hear more? Here are some of its benefits:
- Efficient Use: One of the significant benefits of the SQL database language is that it allows users to quickly insert, update, delete, or retrieve data with simple commands.
- Remote Access: Users can use administrative functions and manage a database a lot easier – as well as remotely access data by using SQL.
- Universally Used: Another benefit of SQL is that it is widely used among various platforms.
Components of SQL
SQL code is often divided into four main categories.
- ‘Queries are performed using the ubiquitous yet familiar SELECT statement, which is further divided into clauses, including SELECT, FROM, WHERE and ORDER BY.
- ‘Data Manipulation Language (DML) is used to add, update or delete data and is actually a SELECT statement subset and is comprised of the INSERT, DELETE and UPDATE statements, as well as control statements, e.g., BEGIN TRANSACTION, SAVEPOINT, COMMIT and ROLLBACK.’
- ‘Data Definition Language (DDL) is used for managing tables and index structures. Examples of DDL statements include CREATE, ALTER, TRUNCATE and DROP.’
- ‘Data Control Language (DCL) is used to assign and revoke database rights and permissions. Its main statements are GRANT and REVOKE.’
Below are some common SQL commands.
- SELECT – used to retrieve data from a database
- INSERT – used to insert data into a database
- UPDATE – used to update data in a database
- DELETE – used to delete data from a database
- CREATE – used to create a new table, database, or view
- ALTER – used to alter the structure of an existing table or database
- DROP – used to drop a table or database
- TRUNCATE – used to remove all data from a table
- JOIN – used to combine data from two or more tables
- GROUP BY – used to group data based on a certain column or expression
- ORDER BY – used to sort data based on a certain column or expression
- WHERE – used to filter data based on a certain condition
- HAVING – used to filter data based on a certain condition after grouping
SQL command examples
SELECT – This command will retrieve all the records from the “customers” table.
SELECT * FROM customers;
INSERT – This command will insert a new record into the “customers” table with the name “John Doe” and email “firstname.lastname@example.org“.
INSERT INTO customers (name, email) VALUES ('John Doe', 'email@example.com');
UPDATE – This command will update the email address of the customer with the name “John Doe” to “firstname.lastname@example.org“.
UPDATE customers SET email@example.com' WHERE name='John Doe';
DELETE – This command will delete the record of the customer with the name “John Doe” from the “customers” table.
DELETE FROM customers WHERE name='John Doe';
CREATE – This command will create a new “orders” table with columns “id”, “customer_id”, and “amount”.
CREATE TABLE orders (id INT, customer_id INT, amount DECIMAL(10,2));
How long does it take to learn SQL?
Already a dab hand at languages and coding principles? If you already know your stuff, then SQL is considered easy to pick up and can be learned in just a couple of weeks. However, if you are new to coding, it can take a little longer. Practice makes perfect!
Learn to code
For many coders who have just begun to express their curiosity about the world of technology, familiarising yourself with the specifics of programming languages can be a challenging task. However, the word task is itself a very valuable clue.
These technologies are just like specific professions tasked with certain duties and expectations. You’re a chef? Your task is to cook. Trained as a teacher? Then your task is to teach. It’s that simple. These technologies are designated with a specific purpose. There is an underlying functionality that makes these programming languages and software useful for modern coders. Otherwise, like the technologies of yesterday, they slip away unnoticed.
- Consider the fact that typewriters, for the most part, are either being used by unemployed writers or by governments to counter the threat of international spying due to how obsolete they have become in a digital world.
- Or that the Wall Street Journal discussed the severe fall in landline phone use between 1996 and 2011, from 96% to 71%.
- When was the last time you used a public payphone, looked up a phone number in a phone book, or searched for a definition in an encyclopaedia?
The world has never changed so much or so quickly. So, are you ready to get with the times and learn to code for yourself?
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