What is SQL? | reed.co.uk

by Amber Rolfe

Looking to learn a new language? Try SQL…

In today’s digital world, data is at the core of almost everything we do — whether it’s browsing the internet, shopping online, or even checking social media. This data needs to be stored, organised, and accessed efficiently, and that’s where SQL comes in. 

Not sure what SQL is? Here’s everything you need to know about SQL, one of the most sought-after skills in today’s job market: 

 

What is SQL? 

SQL stands for Structured Query Language. It’s a programming language specifically designed for managing and manipulating databases. 

Not only does it allow you to interact with a database, retrieve data, insert new records, and update existing ones, it also enables you to delete data that is no longer needed. 

Essentially, SQL acts as a bridge between users and their databases, enabling efficient data handling and storage.

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How does SQL work? 

SQL works by using queries to communicate with databases. A query is a request for specific information or actions, written in SQL syntax. 

When you write an SQL query, you’re telling the database what you want to do with the data — whether that’s selecting a particular set of records, adding new entries, or modifying existing information.

 

What are the basic SQL commands?

Some of the basic commands in SQL include:

• SELECT: Retrieves data from a database. It is often the first command people learn when starting with SQL.
• INSERT: Adds new records into a table.
• UPDATE: Modifies existing records.
• DELETE: Removes records from a database.

These commands form the foundation of SQL and allow users to manipulate data in various ways.

 

What are the key concepts of SQL?

To better understand SQL, it’s important to grasp a few fundamental concepts:

• Databases: A database is a collection of organised data that can be accessed, managed, and updated. SQL is used to interact with relational databases, which store data in tables.

• Tables: A table is a structured set of data, organised in rows and columns. Each column represents a specific type of information, like “Name” or “Date of Birth,” while each row represents a record.

• Queries: A query is a request to perform an action on a database. It could be as simple as asking for all the records in a particular table or as complex as joining data from multiple tables.

• Primary keys: A primary key is a unique identifier for a record in a table. It ensures that each record can be uniquely identified, which is crucial for maintaining data integrity.

• Relationships: Relational databases allow tables to be linked together through relationships. This is often done using foreign keys, which reference primary keys in another table. For example, a table of orders might have a foreign key pointing to a customer table to show which customer placed each order.

 

What is SQL used for?

SQL is used across various industries and roles – from web development to data analysis. Here are some of the most common use cases:

• Web development: Websites and applications often store user information in databases. Developers use SQL to manage user data, such as login credentials and customer details.

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• Data analysis: Data Analysts use SQL to extract, filter, and analyse data from databases. This helps businesses make informed decisions based on their data.

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• Business intelligence: Business Analysts use SQL to create reports and dashboards that track key performance metrics. This helps organisations monitor their performance and identify areas for improvement.

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• Database administration: Database Administrators (DBAs) and Database Developers use SQL to maintain the health and performance of databases, ensuring data is stored securely and efficiently.

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Can you use SQL in Excel?

Yes, you can use SQL in Excel, through Microsoft Query and Power Query. 

Microsoft Query allows you to connect to external databases like SQL Server or Access and run SQL queries directly to extract data into Excel. 

Power Query, available in newer Excel versions, also supports SQL queries when connecting to databases, offering a more user-friendly interface for data manipulation. 

Both methods enable users to leverage SQL’s power for querying and transforming data within Excel.

 

What are the benefits of using SQL?

SQL’s versatility and power make it an essential tool for managing data. Here are a few benefits of using SQL:

• Efficient data management: It allows quick retrieval, updating, and manipulation of data in large databases.
• Versatility: SQL is compatible with various databases like MySQL, SQL Server, and PostgreSQL, making it widely applicable.
• Powerful analysis: It enables complex queries for filtering, joining, and aggregating data, ideal for generating insights.
• Automation: SQL scripts automate repetitive tasks, saving time and ensuring consistency.
• Data integrity and security: Features like constraints and access control help maintain accurate and secure data.

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Is SQL easy to learn?

SQL is considered easy to learn, especially for beginners in programming, and in comparison to other programming languages. 

This is because its syntax is straightforward and similar to plain English, using basic and easy-to-grasp commands like SELECT, INSERT, UPDATE, and DELETE. 

 

How long does it take to learn SQL?

SQL is generally quick to learn, and getting to grips with the basics of SQL usually takes two to three weeks (with consistent practice). 

However, it’ll likely take around six months or more to master the more advanced concepts of SQL – such as JOINs, subqueries, and performance optimization. 

 

How to learn SQL

If you’re interested in learning SQL, there are a number of online resources that’ll help you get started – from tutorials and courses to interactive coding platforms.

This training is available from beginner to advanced levels, teaching you the fundamentals of SQL, and allowing you to apply the concepts of SQL in real-world scenarios. 

 

Ready to start learning? View all SQL courses now.