SQL – Structured Query Language: Introduction, Evolution

SQL is a programming language that is used to communicate and manipulate databases. SQL, which stands for Structured Query Language, is a programming language that is used to communicate with and manipulate databases. In order to get the most of the mounds of data they collect, many businesses must become versed in SQL.

 

SQL programs are put in place by businesses and other organizations as a way to access and manipulate the information and data that is stored in their databases, as well as for creating and altering new tables. To fully understand SQL, it is important to first know exactly what a database is.

According to Microsoft, a database is a tool for collecting and organizing information. Databases can store information about people, products, orders or anything else. Many databases start in a word processing program or spreadsheet, but as they get larger many businesses will find it helpful to transfer them to a database created by a database management system.

In order to control the information in those databases, SQL is used, which allows users to retrieve the specific data they are looking for when they need it. While it is a simple programming language, SQL is also very powerful. The website Database Dir says SQL can insert data into database tables, modify data in existing database tables and delete data from SQL database tables. In addition, SQL can modify the database structure itself by creating, modifying and deleting tables and other database objects.

According to Database Dir, SQL uses a set of commands to manipulate the data in databases. Examples include SQL INSERT, which is used to add data in database tables, the SQL SELECT command to retrieve data from database tables and SQL UPDATE to modify existing database records.

With so many companies now relying on big data analytics to drive their direction, employees with SQL skills and backgrounds are some of the most sought after by employers.

Ibro Palic, CEO of Resume Templates for Mac, told BusinessNewsDaily that SQL is a highly sought-after technical skill due to its ability to work with nearly all databases.

“Every company today that gathers data needs somebody who is able to utilize SQL to quickly pull out key data components and generate reports that aid the decision-making process,” Palic said.

SQL history

The SQL programming language was first developed in the 1970s by IBM researchers Raymond Boyce and Donald Chamberlin. The programming language, known then as SEQUEL, was created following the publishing of Edgar Frank Todd’s paper, “A Relational Model of Data for Large Shared Data Banks,” in 1970.

In his paper, Todd proposed that all data in a database be represented in the form of relations. It was based on this theory that Boyce and Chamberlin came up with SQL. In the book “Oracle Quick Guides (Cornelio Books 2013),” author Malcolm Coxall writes that the original SQL version was designed to manipulate and retrieve data stored in IBM’s original relational database management systems known as “System R.”

It wasn’t until several years later, however, that the SQL language was made available publicly. In 1979, a company called Relational Software, which later became Oracle, commercially released its own version of the SQL language called Oracle V2.

Since then, the American National Standards Institute (ANSI) and the International Standards Organization have deemed the SQL language the standard language in relational database communication. While major SQL vendors do modify the language to their desires, most base their SQL programs off of the ANSI-approved version.

What is SQL?

SQL is Structured Query Language, which is a computer language for storing, manipulating and retrieving data stored in a relational database.

SQL is the standard language for Relational Database System. All the Relational Database Management Systems (RDMS) like MySQL, MS Access, Oracle, Sybase, Informix, Postgres and SQL Server use SQL as their standard database language.

Also, they are using different dialects, such as −

  • MS SQL Server using T-SQL,
  • Oracle using PL/SQL,
  • MS Access version of SQL is called JET SQL (native format) etc.

Why SQL?

SQL is widely popular because it offers the following advantages −

  • Allows users to access data in the relational database management systems.
  • Allows users to describe the data.
  • Allows users to define the data in a database and manipulate that data.
  • Allows to embed within other languages using SQL modules, libraries & pre-compilers.
  • Allows users to create and drop databases and tables.
  • Allows users to create view, stored procedure, functions in a database.
  • Allows users to set permissions on tables, procedures and views.

SQL Process

When you are executing an SQL command for any RDBMS, the system determines the best way to carry out your request and SQL engine figures out how to interpret the task.

There are various components included in this process.

These components are −

  • Query Dispatcher
  • Optimization Engines
  • Classic Query Engine
  • SQL Query Engine, etc.

A classic query engine handles all the non-SQL queries, but a SQL query engine won’t handle logical files.

Following is a simple diagram showing the SQL Architecture −

What’s Your Future with SQL?

Looking back at over 30 years of SQL history, you can see the different stages of its development. SQL 1 in the 1980s (SQL-86, SQL-89) was the first effort to standardize and formalize the definition of the language. SQL-92 provided the foundation for the stable language that we know today, the one that is now the standard data language for all major data technologies.

SQL:1999 and SQL:2003 provided the foundations for modern SQL, with its addition of window functions, Common Table Expressions, and GROUP BY extensions. After 2003, the language reached the phase of stability and maturity. The core language does not change, but new features are added to enhance the existing language and to support emerging technologies, such as XML or JSON.

The SQL standard is no longer a reference for regular SQL users. However, the benefits of having a standard are numerous. The standard:

  • Points out which language extensions are important and useful.
  • Guides the development of SQL implementations in databases and other data processing technologies.
  • Provides the common syntax and semantics that most data processing technologies will implement.

The standard does not guarantee that all SQL implementations are perfectly compatible, but it guarantees that they are for the most part aligned and they all develop in the same direction.

 

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