Structured Query Language (SQL) is a programming language that is used to communicate with and manipulate databases. It has a rich history that dates back to the 1970s.
The origins of SQL can be traced back to the development of the relational model of databases by Edgar F. Codd in the early 1970s. Codd, a computer scientist at IBM, introduced the concept of a relational database, where data is stored in tables with rows and columns, and relationships between tables are established using keys.
In the mid-1970s, IBM developed a prototype implementation of the relational model called System R, which included a query language called SEQUEL (Structured English Query Language) that later became SQL. SEQUEL was based on English-like syntax and allowed users to retrieve and manipulate data in a relational database using a set of standardized commands.
In the late 1970s and early 1980s, other companies and research institutions developed their own relational databases and query languages, which were similar to SQL. These included Ingres, Oracle, and PostgreSQL. In 1986, the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO) standardized SQL as a standard language for relational databases, known as SQL-86.
Since then, SQL has evolved through several versions and standards, including SQL-89, SQL-92, SQL:1999, SQL:2003, SQL:2008, SQL:2011, SQL:2016, and SQL:2019. Each version introduced new features, syntax, and functionality to SQL, making it a powerful and versatile language for managing relational databases.
SQL has become the de facto standard for working with relational databases and is widely used in various industries, including finance, healthcare, e-commerce, and more. It has also inspired the development of other database management systems, such as MySQL, Microsoft SQL Server, PostgreSQL, and Oracle Database, which have their own variations and implementations of SQL.