SQL is a programming language that is used with relational databases.
It is the code used to edit and communicate with the databases. It was standardized in 1986 and is still in popular use today.
With SQL, you can update any information in the relational database, change any entry in the database, make any calculations, and generally manage all inputs and functions of the database.
For someone with limited knowledge of technical jargon, and all things’ databases, it can be a mental fog to figure out where the right place to start is.
That’s why we have put together an SQL guide, to start you on your way and put you in the right direction to becoming an expert on all things SQL.
SQL stands for ‘Structured Query Language’.
SQL is used for a number of different things in relation to relational databases.
The most common uses are as follows:
- SQL is used to gain access to data in relational databases.
- SQL is a language tool to enable data description, aka a way of talking about the data in relational databases.
- SQL makes it possible to both define and manipulate data in relational databases.
- SQL is a way to create tables and set permissions on the created tables.
SQL Overview And Features
So now we’ve got the definitions out of the way, let’s move on to the finer details.
There are different components and rules that come together to make up the overall structure of SQL.
SQL is case-sensitive.
That means some commands must be typed in either full CAPS, and some must be typed in lowercase.
There are, of course, some key terms that anyone SQL curious should get to know a bit better.
Consider the following examples as your diving board into the deep end of SQL. If you continue your journey, you will come across these terms a lot. So, they are worth taking a close note of.
Null, or Null value, is the term used to describe a piece of data that is either missing or not known. It is a way to account for data gaps in relational databases.
Identifiers are as they sound. They are a way to identify the different data components.
Comments are literal comments on the database.
All relational databases have keywords through the SQL statements attached to them. These keywords can be on their own, or in a group of SQL.
Data Definition Language
Data definition language (DDL), is the part of SQL that literally defines the data.
It shapes and molds the relational database. You use the data definition to create tables and cells, delete cells, alter the cells and rename them.
Curious about common DDL terms? We’ve got you covered. Here are four of the most used DDL SQL statements.
- DROP: Essentially a deletion command. Use DROP when you want to get rid of tables.
- INSERT: Use INSERT when you need to insert a new piece of information, or data, into the relational database.
- DELETE: This one is pretty straightforward. DELETE is used when you want to delete a row, either on the database or on a table on the database.
- UPDATE: This is the command that allows you to update the relational database inputs.
Data Manipulation Language
Data manipulation language (DML) is the name for the SQL terms that manipulate data.
With DML you expect to be able to add columns or tables. You can also update the data with DML.
Data Query Language
Data Query Language (DQL) is, as you’ve probably figured out, the component of SQL used to query data on relational databases.
Think of it as asking the database a question regarding its data.
Relational Database Quick Insight
A relational database is a type of database that stores different components of information that are in some way related to one another.
Data is displayed in columns and tables.
Is SQL Easy To Learn?
Yes, and no.
SQL can be learned by anyone with enough motivation to learn it. It is person by person dependent.
SQL takes a lot of mental energy and brainpower. There are a lot, and we mean A LOT, of different components to learn to bring the big, overarching, SQL jigsaw pieces together to form the end picture.
However, with enough studying and practice, SQL can be mastered with a month’s time.
There are a lot of free resources available that you can play around with to try and master SQL.
You will first have to get to grips with relational databases, how they work, and probably learn to create one for yourself to boost your confidence and knowledge base.
SQL Learning Resources
SQL & Relational Databases Downloads
To reiterate, a good place to start learning SQL is by digging into some relational databases.
Learning and understanding how these types of databases work will help you naturally develop your SQL skills and pick it up a lot more easily, and quickly.
Here are two great books that can help you in your SQL learning journey:
These books are both geared towards complete SQL beginners but can be good for going over the basics and building knowledge as well.
Tutorials & Videos
Another great learning resource for SQL is SQL tutorials. Here are a few of our go-to SQL learning tutorials.
Final SQL Thoughts
Standard Query Language is used to assess, define, manipulate, and extract data from relational databases.
It is a standardized language, used globally. It can be easy to pick up if you are feeling motivated enough!
It’s a really useful tool, especially if you are wanting to branch out knowledge-wise.
However you chose to learn, SQL can be a valuable tool for any career in programming, database administration, business analysis, running a business, researchers, educators, even journalists.