Fundamentals of SQL | Deep dive into SQL theory! Chapter 1

In this series we’re going to discuss and learn SQL fundamentals, Why SQL and the most important aspects of SQL.

Are you a data scientist or Data Analyst interested in learning more about how to analyze the data and improve your SQL skills? Then this Series is designed for you.

1) What is SQL

SQL (Structured Query Language) is used to perform operations on the records stored in the database, such as updating records, inserting records, deleting records, creating and modifying database tables, views, etc.

SQL is not a database system, but it is a query language.

This database language is mainly designed for maintaining the data in relational database management systems. It is a special tool used by data professionals for handling structured data (data which is stored in the form of tables). It is also designed for stream processing in RDSMS.

You can easily create and manipulate the database, access and modify the table rows and columns, etc. This query language became the standard of ANSI (American National Standards Institute- is the primary organization for fostering the event of technology standards within us) in the year of 1986 and ISO (International Organization for Standardization — is an international standard development organization composed of representatives from the national standards organizations of member countries.) in the year of 1987.

2) Why SQL

Nowadays, SQL is widely used in data science and analytics. Following are the reasons that explains why it is widely used:

• If you talk about Data Engineer, Data Scientist, Web developer, Full stack developer, it is required in each and every role.
• The basic use of SQL for data professionals and SQL users is to insert, update, and delete the data from the relational database.
• SQL allows the data professionals and users to retrieve the data from the relational database management systems.
• It also helps them to describe the structured data (data which is stored in the form of tables).
• It allows SQL users to create, drop, and manipulate the database and its tables.
• It also helps in creating the view, stored procedure, and functions in the relational database.
• It also allows SQL users to set the permissions or constraints on table columns, views, and stored procedures.

3) History of SQL

“A Relational Model of Data for Large Shared Data Banks” was a paper which was published by the great computer scientist “E.F. Codd” in 1970.

The IBM researchers Raymond Boyce and Donald Chamberlin originally developed the SEQUEL (Structured English Query Language) after learning from the paper given by E.F. Codd. They both developed the SQL at the San Jose Research laboratory of IBM Corporation in 1970.

At the end of the 1970s, relational software Inc. developed their own first SQL using the concepts of E.F. Codd, Raymond Boyce, and Donald Chamberlin. This SQL was totally based on RDBMS. Relational Software Inc., which is now known as Oracle Corporation, introduced the Oracle V2 in June 1979, which is the first implementation of SQL language. This Oracle V2 version operates on VAX computers.

4) Advantages of SQL

SQL provides various advantages which make it more popular in the field of data science. It is a perfect query language which allows data professionals and users to communicate with the database. Following are the best advantages or benefits of Structured Query Language:

• No programming needed
  SQL does not require a large number of coding lines for managing the database systems. We can easily access and maintain the database by using simple SQL syntactical rules. These simple rules make the SQL user-friendly.
• High-Speed Query Processing
  A large amount of data is accessed quickly and efficiently from the database by using SQL queries. Insertion, deletion, and updation operations on data are also performed in less time.
• Standardized Language
  SQL follows the long-established standards of ISO and ANSI, which offer a uniform platform across the globe to all its users.
• Portability
  The structured query language can be easily used in desktop computers, laptops, tablets, and even smartphones. It can also be used with other applications according to the user’s requirements.
• Interactive language
  We can easily learn and understand the SQL language. We can also use this language for communicating with the database because it is a simple query language. This language is also used for receiving the answers to complex queries in a few seconds.
• More than one Data View
  The SQL language also helps in making the multiple views of the database structure for the different database users.

5) Disadvantages of SQL

With the advantages of SQL, it also has some disadvantages, which are as follows:

• Cost
  The operation cost of some SQL versions is high. That’s why some programmers cannot use the Structured Query Language.
• Interface is Complex
  Another big disadvantage is that the interface of Structured query language is difficult, which makes it difficult for SQL users to use and manage it.
• Partial Database control
  The business rules are hidden. So, the data professionals and users who are using this query language cannot have full database control.

6) Career In SQL

If you want to get a job in the field of data science, then it is the most important query language to learn. Big enterprises like Facebook, Instagram, and LinkedIn, use SQL for storing the data in the back-end. There are many companies that use SQL that are searching for SQL experts.

One example of the use of SQL is in social media platforms. Facebook, for instance, stores millions of users’ profile information and posts in database systems. To access these databases, programmers need to use a programming language such as SQL to work with the data.

Experienced developers use SQL in data management, data analysis, and customer relationship management. It is used by businesses, programmers, and analysts to make better business decisions.

SQL is a standard language used by organizations for data management and administration. Almost every big organization uses it to record employee data and confidential company information.

Their database administrator uses SQL to update and add information to their online database. Other sectors that use SQL for database management purposes are hospitals and schools.

7) Job Role and Domain

• Data Analysis
  SQL is commonly used by data engineers, data scientists, and data analysts in software development because it is fairly easy to learn the language and its basic features. It can be used for direct access to an actual database without needing to download data first.
• Marketing
  It is used to sort through customer demographics and find the right target audience. Analyzing information using SQL helps organizations come up with better marketing campaigns for the future.
• Backend Development
  SQL is frequently used in backend development for gathering, inserting, and updating data. By using SQL for these tasks, they ensure that the backend of applications and websites runs smoothly and that data corruption is prevented. SQL is also great at helping backend developers locate and resolve bugs and glitches.
• Accounting
  SQL is used by accountants because of its functions for storing and manipulating data. It allows accountants to easily find the information they are looking for and update it to reflect the new, current information. As well, SQL helps accountants make better business-related decisions.
• Database Administrator
  A DBA’s function is to analyze an organization’s data management, input, and security requirements, by helping develop processes that support access and information security for the data stored within SQL Server databases. While a SQL Server DBA only writes code on specific occasions, they do play an essential role in optimizing SQL queries and oversee backups, audits, and data replication to ensure that SQL databases remain accessible, secure, and stable.
• Data Scientist
  A Data Scientist is someone who is an analytical expert and utilizes their skills in both business, technology, and social science to find trends and manage data at a massive scale.

8) Why Use SQL for Business and Finance?

Knowledge of the SQL programming language allows Financial Analysts to build more advanced database systems which are built on a format that is very similar to a spreadsheet.

Especially as the collection of data has become an essential part of multiple fields and industries, knowledge and understanding of databases is required when working with big data. For businesses and financial institutions, it is also important to ensure that the data being collected can be stored in a safe and secure space, and there are several SQL tools that specialize in the security of the information and data being stored, as well as the collection of financial data, such as user transactions and business trends.

In addition to using SQL to communicate with relational databases, SQL databases work well with other programming languages and data science libraries. Learning SQL can be viewed as just the beginning of developing advanced knowledge in other programming languages, such as R and Python. Python can be used libraries like NumPy and SciPy, to handle complex mathematical equations, as well as create financial models, Predictive Models and risk assessments.

SQL for Data Analysis — with SQL Server is a online class taught live by experts from leading Companies like Bajaj.

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