Welcome to another entry in Shortcut Talks About Engineering Stuff, a series whose title is pretty self-explanatory. We can talk about data, we can try to troubleshoot, we can talk about how we go about it internally when building a new project, and we can write a quick start guide for a programming language, and that's what we've done here in this broad overview of it , HowTtake you from nothing about SQL to knowing something about SQL and knowing a lot about SQL.
Ah, SQL. We love SQL, don't we? Is there a cooler set of initials somewhere in the tech?
Wait, sorry, I confused SQL reputation with another language, didn't I? Maybe go? Wait, is Go still legal?
How many questions can we open this post with? It's about seven now, right? Is there a Guinness World Record for most of the questions asked at the beginning of a blog post?
OK. SQL isn't necessarily that cool, but it's important if you want to do any work that involves itData. SQL skills are inhigh demandeverywhere, especially with companies like Netflix and Spotify, whose appeal and growth depends heavily on how users interact with their services.
Even if you don't plan to join the data team anytime soon, it's worth taking the time to learn a little about SQL. You will gain a better understanding of how databases are built and how they interact, making you more complete. And that's cool in its own way.
So where should you focus your efforts? Don't worry, this step-by-step guide - we think it's a list, or should we say liSQL - has you covered.
Get started with Shortcut today!
SQL for beginners
If you're only vaguely familiar with SQL (aka Structured Query Language), focus on learning some of the core concepts and ideas behind it. An understanding of SQL databases, tables and indexes and the ability to write a simple query will put you in an excellent position to understand the purpose and key applications of SQL.
If you find that you might not be able to write a simple SQL query that's a bit offensive, we recommend skipping to the next section.
1. Database Basics
To understand the purpose of SQL, you must first understand the concept of a database. What's worth it? How can these electronic filing systems help companies to organize and use data in a meaningful way?
A better understanding of the role of databases and how they are used prepares you to understand the functionality of SQL and the role it plays in your own organization.
Learn more: Basics of the database system
2. The purpose of tables and indexes
Tables and indexes are the main building blocks of SQL. It can help to think of the database as a library, the tables as individual books, and the indexes as one of those old-fashioned Dewey decimal files that help you find what you're looking for.
While knowing how they actually work is a more advanced skill, it's important to understand what they are and what they do so you can effectively navigate the data in your database.
Learn more:Database Indexes Explained
3. Basic SQL syntax
To understand a programming language, you must first understand its syntax. In SQL, this means understanding how to create a query to find relevant information.
learn the basicsCHOOSEeVONCommands to create a functional query that extracts data from a table. SQL is incredibly accurate, and small mistakes can lead to big problems later, so spend some time learning how to avoid themcommon syntax errors, like keyword errors and misspelled quotes.
Learn more: Learn SQL for beginners in 5 steps in 5 minutes
4. Conditional filters
You don't always want to retrieve all records from a particular column. Typically, your requirements are a bit more specific. Once you understand how a query is structured, you'll learn to write a slightly more advanced query so you can extract the information you need from a table.
WOClauses help you filter your table, along withOReE.GROUP BYeSORT BYhelp you organize the data you have retrieved. Once you've learned this, you'll know how to write most basic queries.
Learn more:How to filter query results
Intermediate level SQL skills
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If you already know the basics of SQL and how to query a database, you can hone your skills with some more advanced features and deeper theoretical knowledge. These skills are a bit more complicated, and like anything more complicated, they can take longer to fully understand.
5. Together
Not all the data you need to work with is always in a table; In fact, most of the time it won't be. By mastering joins, you can bring data from multiple tables together. This greatly simplifies the analysis of different data sets.
There are four types of joins: inner, left, right, and full. You need to learn which ones to use, when, and the code you need to run them.
Learn more:Basic SQL join types
6. Subqueries
A subquery, sometimes called a nested query, is a query nested within another statement. Like joins, they are used to join data between different tables, but when done well, they are faster and more efficient than joins because they eliminate extra data steps when extracting data.
Learn when and where to use subqueries instead of joins, and learn to writeReadable and maintainable SQL using common table expressionseven as your subqueries get more complex.
Learn more: Introduction to a subquery in SQL
7. How Indexes Work
Database indexes speed up queries. By enforcing order in data tables, indexes make it easier to query to find the information you want.
Understanding how (and why) indexes are created and the different types will give you a better understanding of how to use them effectively. Learn the difference between clustered and non-clustered indexes, how indexing adds data structures, and the rules for creating efficient indexes.
Learn more: This is how indexing works
8. Gain hands-on knowledge of PHP
lol You're already working hard to learn SQL and now we're telling you to start learning PHP too?
It's a lot to ask, but some mastery of PHP will help you connect to many popular SQL database programs such as MySQL. You can build almost any type of website using both together. So if you go all-in, you really should go all-in.
Learn more: PHP and MySQL Tutorial
9. How to work with common database systems
SQL itself is just a programming language. To actually store data, you need to work with a system like MySQL or PostgreSQL. Both are open source and freely available and use similar syntax, so it's a good idea to try and master both.
Learn more:PostgreSQL x MySQL
Advanced SQL knowledge
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If you're already familiar with a database and can work with common database management systems, you're probably feeling pretty good right now. At least if working with databases is something that makes you feel good. But there is always more to learn.
10. Execution Plans
Execution plans are a visual representation of how a database engine executes a query. They basically let you look under the hood and see how the information sausage is made.
Execution plans can tell a lot about the efficiency of a query and are the primary tool for troubleshooting slow or poorly executed queries. Reading and understanding them will help you optimize your queries without impacting performance. Learn how to extract, read, and tune an execution plan to increase query performance.
Learn more: Execution plan in SQL Server
11. Back up databases
Creating a backup database is crucial in case the first one is corrupted or corrupted in any way. There are different types of backups, and knowing which ones to use and how to set them up (and restore them) is an important part of database management.
Learn more:Familiarize yourself with the SQL Server backup types
12. Using indexes to speed up SQL queries
indices canspeed up performanceThis makes data more discoverable, but poor indexing is also one of the biggest performance killers. Learning how to identify good index candidates and how to create and maintain them will help you maintain a fast and tidy database.
Learn more:SQL Query Performance Killers - Understanding Poor Database Indexing
13. OLAP
Online Analytical Processing (OLAP) describes a class of database applications that allow you to analyze data faster and in more innovative ways than a simple two-dimensional spreadsheet. Previously this was mostly in the form of OLAP cubes, howeverdeveloped in recent yearsto run OLAP workloads directly against columnar databases.
It requires a lot of advanced skill to implement, but OLAP can help you process numbers in interesting ways that help you understand a business.
Learn more:OLAP-Tutorials
Further development of your SQL knowledge
What SQL lacks in freshness, its community makes up for in enthusiasm. The internet is full of amazing free resources to help you learn more about the wide world of SQL. Inspecial blogsforonline coursesforactive communitiesFor the SQL developer, there are almost endless ways to learn more.
Start with the basics, work your way up, and before long you'll be a database master. And that's really cool.
You know what else is cool but doesn't require SQL or database skills? Using Shortcut to manage your projects. Sign up and try us for free to see how cool it is.
If you have questions about Shortcut, visit our hep center.We are here to help. And also to manage projects. But mostly to help.
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