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What Is SQL?

SQL, or Structured Query Language, is a domain-specific language that’s been in use since the 1970s. It’s still widely used in analytics, data engineering and data science to help manage data stored in a relational database system and can be vital when working with structured data. SQL allows programmers to query, update and reorganize data as needed while also modifying database schema to control data accessibility. MySQL and PostgreSQL are two of the most popular open-source relational database management systems while some common enterprise-level systems that utilize SQL include Oracle, Sybase, Microsoft SQL Server, Access, Ingress and many other proprietary extensions.

 

How Does SQL Work?

SQL is considered to be the most important tool at the disposal of anyone who works with data, from data scientists to engineers and statisticians as it is used to access, query, update and reorganize data within a database.

At its core, a database is simply a system for organizing data stored on disk. Relational databases work by storing structured data within tables. These tables make up the database schema, and oftentimes, these tables will be linked together through one or more common fields. These relationships between common fields allow users to access data from separate tables simultaneously upon user query. This process is called joining tables.

The tables and data within databases are stored in separate files on disk for easy access and permanent storage compared to data stored in memory. Understanding the database’s file system is an important part of architecting data intensive applications, but is not a requirement for learning and using SQL. 

For relational databases that use SQL, an SQL engine and query optimizer are used in conjunction with the file system. Together, they interpret and execute the SQL commands. The query engine transforms the SQL into something the computer can understand while the query optimizer finds the optimal way to retrieve the data from the files. The foundations of SQL and query optimization stem from relational algebra, but SQL is easy to learn and apply without knowing the theory upon which it was built.

SQL remains popular due to its relative ease of use for beginners. Standard SQL commands, such as “select,” “insert,” “update,” “delete,” “create” and “drop” can be used across all databases to accomplish virtually any task in SQL.

Related Reading From Built In ExpertsWhy SQLZoo is the Best Way to Practice SQL

 

What Is SQL Used For?

Generally, we use SQL to communicate with a database. Every company stores data to some extent, which means having the skills to access and manipulate data can result in a high-paying career.

SQL is highly useful when it comes to managing structured data in an organized manner, making it easy to quickly access and arrange data.

  • Data analysts rely on SQL to quickly pull and aggregate data from a database.
  • Data engineers rely on SQL to move volumes of data through various systems.
  • Data scientists rely on SQL to quickly analyze and clean data before using it in complex modeling.

SQL is particularly useful due to its ability to share and manage data found in a relational database management system, which allows users to query, update and reorganize key data, while also modifying database schema and determining how data can be accessed.

Due to these capabilities and use cases, SQL has become the most widely implemented programming language despite being created in the early 1970s.

What Is SQL? | Video: Danielle Thé

 

Should I Learn SQL or Python?

Oftentimes, working with structured data requires fetching the data in SQL and manipulating it in Python, so the short answer: Learn both if you can.

SQL is excellent for querying, extraction and merging tables from databases together to provide users with robust but specific datasets. SQL is not, however, the best choice when it comes to transforming data into other formats, which is often utilized in the form of regression testing and time-series data manipulation in data science. Python is the better option for tasks of this nature, particularly through its Pandas library, which is tailor-made for data manipulation and analysis.

Courses

Expand Your SQL Career Opportunities

Learn SQL with one of Udemy’s top-rated courses.

Udemy

Topic:

Learn how to formulate and tune SQL statements for optimal performance

 

What you'll learn:

  • Identify poorly performing SQL

  • Understand how the…

4.2
(1158)
Udemy

Topic:

SQL that will get you hired – SQL for Business Analysis, Marketing, and Data Management

 

What you'll learn:

  • Become an expert in SQL

  • Learn how…

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Udemy

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Become an In-demand SQL Master by creating complex databases and building reports through real-world projects

 

What you'll learn:

  • Create your own database or…

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Udemy

Topic:

Become an expert at SQL!

 

What you'll learn:

  • Use SQL to query a database

  • Use SQL to perform data analysis

  • Be comfortable…

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Certifications

SQL Certifications + Programs

Udacity’s SQL and other related certifications can give your resume the boost it needs to take your career to new heights.

General Assembly’s Data Analytics Immersive is designed for you to harness Excel, SQL, and Tableau to tell compelling stories with a data driven strategy. This program was created for analysts, digital marketers, sales managers, product managers, and data novices looking to learn the essentials of data analysis. 

 

What you'll accomplish

You will learn to use industry tools, Excel, and SQL to analyze large real world data sets and create data dashboards and visualizations to share your findings. The Data Analytics Accelerator culminates in a.

Throughout this expert-designed program, you’ll:

  • Use Excel, SQL, and Tableau to collect, clean, and analyze large data sets.
  • Present data-driven insights to key stakeholders using data visualization and dashboards.
  • Tell compelling stories with your data.
  • Graduate with a professional portfolio of projects that includes a capstone project applying rigorous data analysis techniques to solve a real-world problem

 

Why General Assembly

Since 2011, General Assembly has graduated more than 40,000 students worldwide from the full time & part time courses. During the 2020 hiring shutdown, GA's students, instructors, and career coaches never lost focus, and the KPMG-validated numbers in their Outcomes report reflect it. *For students who graduated in 2020 — the peak of the pandemic — 74.4% of those who participated in GA's full-time Career Services program landed jobs within six months of graduation. General Assembly is proud of their grads + teams' relentless dedication and to see those numbers rising. Download the report here.

 

Your next step? Submit an application to talk to the General Assembly Admissions team


 

Note: reviews are referenced from Career Karma - https://careerkarma.com/schools/general-assembly

 

Udacity
Beginner
2 months
10 hours

General Assembly’s Software Engineering Immersive is a transformative course designed for you to get the necessary skills for a coding role in three months. 

The Software Engineering bootcamp is led by instructors who are expert practitioners in their field, supported by career coaches that work with you since day one and enhanced by a career services team that is constantly in talks with employers about their tech hiring needs.

 

What you'll accomplish

As a graduate, you’ll have a portfolio of projects that show your knowledge of fundamental programming concepts, as well as experience with languages, frameworks, and libraries that employers demand. Throughout this expert-designed program, you’ll:

  • Create a front-end web application with modern JavaScript frameworks such as Angular or React.

  • Develop and deploy full-stack applications with in-demand technologies such as Ruby on Rails, Python with Django, and Express with Node.js.

  • Build secure full-stack applications by leveraging common design and architectural patterns like model–view–controller (MVC) and Representational State Transfer (REST).

  • Practice version control and collaborative software development with Git and GitHub.

  • Safely model and store data in SQL and NoSQL databases.

  • Consume and integrate third-party application programming interfaces (APIs) in an application.

 

Why General Assembly

Since 2011, General Assembly has graduated more than 40,000 students worldwide from the full time & part time courses. During the 2020 hiring shutdown, GA's students, instructors, and career coaches never lost focus, and the KPMG-validated numbers in their Outcomes report reflect it. *For students who graduated in 2020 — the peak of the pandemic — 74.4% of those who participated in GA's full-time Career Services program landed jobs within six months of graduation.  General Assembly is proud of their grads + teams' relentless dedication and to see those numbers rising. Download the report here.

 

Your next step? Submit an application to talk to the General Assembly Admissions team

 

 

Note: reviews are referenced from Career Karma - https://careerkarma.com/schools/general-assembly

Udacity
Beginner
2 months
10 hours

Perform analysis on data stored in relational and non-relational database systems to power strategic decision-making. Learn to determine, create, and execute SQL and NoSQL queries that manipulate and dissect large scale datasets. Begin by leveraging the power of SQL commands, functions, and data cleaning methodologies to join, aggregate, and clean tables, as well as complete performance tune analysis to provide strategic business recommendations. Finally, apply relational database management techniques to normalize data schemas in order to build the supporting data structures for a social news aggregator.

Udacity
Beginner
2 months
10 hours
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