What is SQL and why it is used ?
SQL is an essential language to know if you want to work with data. We talk about SQL, how it's used, and what kinds of jobs you could get if you know SQL.
Data is all around you, from the prices of items at your local grocery store to the personal information that social media sites collect when you use them. Our world is made up of data, and SQL makes it much easier to find our way around this data.
In this post, we'll talk about what SQL really is and what we can do with it. We'll also talk about how to learn SQL and some jobs you could get if you learned the language. SQL is something you'll need to know if you want to work in the data industry.
What is SQL ?
SQL is a programming language used to talk to databases. SQL, which is often pronounced "sequel," is used in a database management system to store, retrieve, manage, and change data.
IBM made SQL in the early 1970s, and it was first sold commercially in 1979. It is the standard relational database management system worldwide (RDBMS).
It uses groups of words called "statements" to get information from databases. These groups of words are called "keywords." Let's check out some of the SQL statements.
If you didn't know SQL, finding the information you need in an extensive database would take much longer. With the SELECT statement, you can choose data based on the table and column type. This way, you can quickly find data sets that meet your search criteria instead of spending a lot of time looking for them by hand.
You can add new information to the tables with the INSERT statement. Like the SELECT statement, you can choose more than one column to put your information in.
The DELETE statement does precisely what its name says: it lets you eliminate records that are already in a table. You can also tell a DELETE query which rows should be deleted based on certain conditions.
The CREATE DATABASE statement is the first step in setting up your database, and it is used to create a new database in your database management system. Once the database has been made, CREATE TABLE is used to make a new table.
The UPDATE statement is used to make changes to one or more database records. You can change all the rows at once, or you can use a condition to change only some.
What is Database ?
Databases are everywhere because almost every business needs to store information digitally. A database is a collection of arranged data that is put together to make it easy to access, store, sort, retrieve, and search.
There are different kinds of databases; the one you choose will depend on the information you want to store. Let's check out a few of the most common types of databases:
- Relational databases are made up of rows and columns, store and give out data in multiple tables, and let you find and use the data about each other. All relational databases use SQL, and relational database management systems are like Microsoft SQL Server.
- NoSQL databases do not use SQL as their primary programming language. People who don't want their data to be as organized should use these databases. We'll talk about these databases more in the future. One example of a NoSQL database is CouchDB.
- Cloud databases are databases that run in the cloud. Access to these databases is provided as a service, and they are easy to take care of and flexible. One example of a cloud database is the Oracle Autonomous Database.
- Time series databases have been set up to work best with time-stamped data, giving more accurate insights. One example of a time series database is Druid.
What is SQL used for?
So, now that you know what SQL is, you might wonder what it is used for. We've already said that it's a programming language used to talk to relational databases. But let's look into that a bit more.
SQL lets you ask questions about a database in many different ways, using statements that look like English (we discussed some examples earlier). It is used on websites to store and process data on the back end (Facebook is a site that uses this).
SQL is used in many places besides Facebook, including music apps like Spotify, banking apps like Revolut, and other social media sites like Twitter and Instagram. SQL is the most popular database language, so almost any business that needs to store relational data can use it.
Queries in SQL are used to get information from a database, but not all questions are as good as others. This is because many databases have proprietary extensions unique to their system.
Essentially, SQL provides CRUD functionality for databases. What does CRUD stand for?
Types of SQL commands
The language can be broken down into four types of SQL commands – DDL, DML, DQL and DCL. Let’s look at what each of these sections are:
- DDL, or "data definition language," can create and change database objects like tables, users, and indices.
- DML, "data manipulation language," is used to delete, add, and change data in databases.
- DCL, which stands for "data control language," controls who can see what data is in a database.
- DQL, "data query language," is used to search through data and find information. It is made up of only COMMAND statements.
Tools are available to help you write SQL; some tools include Microsoft’s SQL Server Management Studio, DataGrip, Oracle’s SQL developer, SQL Workbench and Toad.
SQL vs NoSQL
In the late 2000s, NoSQL databases became popular because they could store data upfront with less need for structure. These databases are more accessible for developers to work with, and they can run queries faster and have more flexible data models.
On the other hand, SQL-based databases are used only for relational data, and they let you operate queries in different ways, are well organized, and store less data. SQL databases are used much more often than NoSQL databases but are often used together.
There are some major differences between the two, these include:
Scalability: Most NoSQL databases can grow by adding more rows, while most SQL databases tend to grow by adding more rows. NoSQL databases can usually handle more people using them at once.
Structure: The structure of SQL databases is based on tables, but NoSQL databases can be found on graphs, documents, or vast column stores. SQL databases are better for transactions that involve more than one row.
Knowledge and community: SQL is more common and has been around longer, so there is a lot of information and communities for it. There aren't as many forums and resources for NoSQL, so it may be harder to find help when you need it.
Types of SQL Jobs
Learning SQL will open up opportunities in a range of different careers; let’s take a look at some of the options available:
- Data scientist - A data scientist is an expert at analyzing large amounts of data. They collect, research, and make sense of big data from many different sources to solve problems. Data scientists need to know SQL because databases are at the heart of their work, and this is because they have to do data analysis.
- Software engineer - A software engineer comes up with and builds software for computer systems and applications. To make software as a software engineer, you must know how to use programming languages. Most programmers also need to know a little bit about SQL.
- Business analyst - A business analyst looks at data and writes down information about the market to help businesses make decisions. This job has much to do with SQL because it involves a lot of data, and you'll work with relational databases.
How to learn SQL
At first, taking the first step to learn a programming language may seem scary, but if you are patient and work hard, you can reach your full potential. Start with the basics, and then, when you're ready, move on to more advanced commands.
Thankfully, we at sysiit have professional subject matter experts who will teach you SQL or any other languages and make your learning journey enjoyable with their years of teaching experience.
Have any questions about this article? Feel free to ask our Subject Matter Expert at 905-629-3000
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