blog posts

Meetings have become one of organizations’ and companies’ most valuable assets. Using data analysis, I can determine organizations’ profit and loss, and the information obtained can provide useful solutions to improve business. SQL (Structured query language) is one of the most important and practical tools for processing, manipulating, and providing reports based on data stored in databases.

SQL” (Structured Query Language | SQL)

This article is based on the answer to SQL and other topics related to who is paid.

To answer the question of what QL is, it is necessary first to provide a brief description of the topics related to this similar language, types of databases and “Database Management Systems” (Database Management Systems | DBMS) so that those who are interested in this language. It is better to understand its use. Also, in this article, a brief history of the SQL language, the advantages and disadvantages of this language, and the main commands are mentioned.

What is data and information?

To answer the question of what SQL is, the concept (data) must be explained because the SQL language is used to access data and change it. Data is raw information collected from sources in different formats, such as numbers, text, audio, and photos. In computer science, data is converted into binary numbers to be processed efficiently. Data in the field of concepts related to the database refers to all the items stored in tables in the database.

For example, a table with the title “Customer” can have a column with the title “Phone Number” that can somehow be received as a text type, and only texts can be stored in this column.

The data is stored in the database in raw form, and when a report is prepared from it or processing is applied to it, the final result is provided to the user as “information” (information).

For example, a table titled “Bank Account” that contains columns such as “Customer Name”, “Account Type”, “Account Balance”, “Contact Number,” and “Address” is given raw products in the form of “Records”. records) or table rows.

When customer accounts are needed, they are short-term information, thus providing the user with useful information for further review and analysis. The following will explain the database and how data is stored in it.

What is a database?

Before explaining the answer to the question, what is SQL? First is the question of what a database is addressed because SQL manages and changes database tables.

A database is a collection of raw or structured data stored electronically in a computer system.

In other words, I can think of the database as a library where I can store the available books. In this example, the data is library books.

The data is stored in rows and columns and as a table in the database (here, the table means only the tables in the relational database) to enable processing and querying on the data. Using SQL, data can be easily accessed, managed, changed, updated, controlled, organized, and modified.

The first databases, which included two types, “Navigational Database” and “Network Database,” were presented in the early 1960s.

Trace-based database: Hierarchical databases are a type of trace-based database. Their structure is in the form of a tree, and records can be found in it by following their references. In this type of database, only one-to-many relationships are used to create relationships between tables.

Network database: In this type of database, the modeling of “Entity” is such that each “Child Entity” can have more than one “Parent Entity”.

It was easy to work with these two types of databases, but they were not highly flexible. For this reason, in the 1980s, the “Relational Database” (Relational Database) was proposed, which will be explained below.

What is a relational database?

Answering the question “What is SQL?” also requires understanding the relational database concept. A relational database is a type of database that can store data in multiple related tables. Its structure is similar to that of Excel spreadsheets.

Database tables can be considered the same as “extended layers” (Sheets) of the Excel program. Each table in the database contains rows and columns, where the rows represent data values and the columns represent “attributes”.

A “Database Management System” (DBMS) is used to access the database and process the data using the SQL language.

What is a database management system?

To answer the question “What is the SQL language and what is its application?” one should also understand the concept of a database management system and its relationship with the SQL language. A database management system is software installed on a personal computer or server to manage databases.

One type of database management system is a “Relational Database Management System” (RDBMS), which is used to create, update, manage, and perform various processes on the database. With RDBMS, data can be stored in the form of a table, and querying can be done using the SQL language.

The most common relational database management systems that use SQL are listed below:

• Sybase
• Microsoft SQL Server
• Oracle
• Ingres
• Access

After explaining the necessary concepts related to the SQL language, the next section will answer the question of what the SQL language is and what its uses are.

What is SQL?

“Structured query language.” SQL (Structured Query Language | SQL) is a language used to manage and communicate with the database. In other words, it can be used to create a database, delete and update information, and extract data from a relational database. This language is one of the American National Standard Institute (ANSI) languages presented by IBM researchers in 1970.

Other versions of this language, such as T-SQL and PSQL, have also been developed by other companies, such as Microsoft and Interbase/Firebird. Although an effort was made to standardize its use, some commands are different in different relational databases.

The capabilities that the SQL language provides to its users are as follows:

The SQL language allows users to access data in an RDBMS.

The data in the relational database can be described in SQL.

SQL allows users to store and manipulate data.

You can access the data in the database with SQL libraries in other programming languages and using SQL commands.

With the SQL language, you can create and delete the database and all its objects, such as tables, routines, views, and other items.

Using SQL, different users can be given different access levels and manage how to access the data stored in the database.

What is the history of SQL language?

Now that the question “What is SQL language” has been answered, this section will discuss the history of this language and its evolution.

The first computerized databases were introduced in the late 1960s. In this decade, many computer science researchers focused on improving database use. One of these researchers was Edgar Frank Ted Codd, a computer engineer at IBM.

In 1970, Codd introduced relational databases in computer science by presenting an article entitled (A Rational Model of Data for Large Shared Data Banks. Thus, this person is usually mentioned as the person who presented the SQL language for the first time.

When Codd published his paper, people were using Network and Hierarchical Databases. These databases were not flexible. In other words, to extract data from them, programming was required, and non-programmers could not access the data.

History of the SQL language

In his article, Codd proposed a new idea using the mathematical concept of relationships based on data modeling, which today are called tables. This type of database was more flexible compared to network and hierarchical databases. It was possible to add new relationships to previous relationships without the need to change the existing relationships, making it easier to work with the database.

System R project

When the Codd model was proposed in 1970, it was not well received, and IBM abandoned implementing Codd’s proposal and idea. At the time, IBM researchers worked with a hierarchical database called IMS. Three years later, in 1973, IBM started a project called System R to explore Codd’s ideas about the relational data model. At that time, Codd did not work closely with the System R project development team, and two other researchers, Don Chamberlin and Ray Boyce, were responsible for implementing the query language.