From the course: Complete Guide to SQL for Data Engineering: from Beginner to Advanced

What is SQL and why learn it? - SQL Tutorial

From the course: Complete Guide to SQL for Data Engineering: from Beginner to Advanced

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What is SQL and why learn it?

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- [Instructor] Whenever you want to share thoughts with your loved ones or you want to communicate with them, you use your own native language. Similarly, whenever you want to communicate with database, the language for communication is SQL, which stands for structured query language. It allows you to talk to databases, to store information, retrieve information, and perform powerful operations on your data. To appreciate what SQL brings to the table, I thought we should delve into a bit of history as to how we used to store and retrieve the data before it came into picture. Before SQL, the data was stored as either a paper files, or a flat files, or hierarchical databases, or in the form of network database. Imagine that you are running a successful online store and your inventory is growing faster than ever. You started with simple spreadsheet. Maybe you are using Microsoft Excel to put all your order, product, all those information into an Excel. But as your store is growing, it's become a nightmare to keep track of everything in terms of an Excel. Orders are getting lost, and customer are frustrated because you might not able to pull out the correct information. Or you might find it very difficult to manage all of these things. That's where the SQLs comes to the rescue. So such kind of a problem exist before the start of the SQL. Now, coming back again to the SQL, SQL is a programming language which is used for controlling and manipulating the structured data, which is present in your databases. SQL allows Juniper to manipulate the data present in databases with the help of queries. And the good thing is that these queries is a kind of an high-level language. That means it's a very human friendly. It is not as complex as writing the programming language, for example, C, C++, Java. So SQL, it's quite easy to comprehend. SQL serves as standard database language for many relational database management systems. For example, MySQL, MS Access, Oracle, and many more. Now as the name comes in, RBDMS, a question might have popped up in your brain that what does this RBDMS stands for? So RBDMS, it stands for relational database management system. A relational database is a form of a database that stores the data in terms of a table so that it can be used in relationship with other tables. So in RDBMS, you create multiple tables, and this table have some kind of relationship between them, and that's why this entire system is called as RBDMS, that is relational database management system. For example, imagine that you are holding the information about a company. Now in a company, you have an entities like employee. In that case, you store the information of the employee in an employee table. Similarly, you will have a department also in the company, and department table keeps a track of all the departments. Now every employee is a part of a sum department, right? So it belongs to a specific department, and that's why there is a relationship between employee and department table, and that's how the relationship is built. So this is about the SQL. Now the question comes in why you should learn SQL. So SQL is a universal language. The best part with the SQL is SQL is not a database specific, as we saw in the previous slide. That SQL is common for multiple databases, whether it is MS SQL, or either MySQL or IBM Db2 or Postgres. So SQL is quite similar everywhere. Hence, knowing an SQL helps you to work with any kind of databases. SQL is very efficient in handling the huge amounts of data. Your databases holds the structured data, the data which has a sum fixed schema. For example, when you store the data into the database, you define the tables, and table has a sum fixed format, like every table have some specific set of column and their data types. So handling such kind of an structured data is very easy to do with SQL. And even SQL can manage such a structured data even without worrying about the size of this data. So whether you have a small size of a data or you have a bigger size of a data, SQL can handle all these types of data. Another advantage of learning the SQL is business application implementation. Many business applications and software systems rely on databases to store and retrieve the data. SQL is the language that facilitates that seamless connections between applications and databases and making it essential for the developers and IT professionals. Another reason could be is scalability. As the data volumes grows, the importance of having the scalable solution is important. SQL knowledge helps in writing efficient queries and optimizing database performance, ensuring that the system can scale to handle increased amounts of data. Last but not the least, it helps in the job opportunities. Many job roles in the field of data analysis, business intelligence, web development, and software engineering, all of them requires SQL proficiency. Learning SQL opens up a wide range of career opportunities and enhances your marketability in the job market. So by now you have understood the very important role of the SQL. Now in the next session, we are going to deep dive into an importance of SQL in the world of the data engineering. And we will see how SQL can play a significant role in making your career in data engineering.

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