SQL Was Renamed Because of an Aircraft Trademark
In the early 1970s, IBM researchers Donald Chamberlin and Raymond Boyce designed a language to query databases using English-like syntax. They named it SEQUEL, for Structured English Query Language. However, when IBM attempted to register the name, they discovered that "SEQUEL" was already a registered trademark of the British Hawker Siddeley aircraft company. IBM shortened the name to SQL, though developers still pronounce it "sequel" to this day.
The Birth of a Relational Query Language
In 1970, computer scientist Edgar F. Codd published a landmark paper introducing the relational model for database management. Codd proposed that data could be stored in tables consisting of rows and columns, with relationships between tables defined logically rather than through rigid, predefined physical pointers. While Codd's mathematical formulations offered a rigorous foundation for organizing data, they relied on relational calculus and relational algebra, which were difficult for ordinary programmers and non-technical business users to navigate directly.
Working at IBM's San Jose Research Laboratory in the early 1970s, researchers Donald D. Chamberlin and Raymond F. Boyce set out to make relational databases practical and accessible. They aimed to design a language that retained the mathematical power of Codd's model while adopting a readable, English-like syntax. The result was a query language built to manipulate and retrieve data stored in IBM's experimental relational database system, known as System R.
From SEQUEL to SQL
Chamberlin and Boyce initially named their creation SEQUEL, an acronym for Structured English Query Language. The name reflected their goal of allowing users to construct queries using familiar English words like SELECT, INSERT, UPDATE, and DELETE. By structuring operations around English commands, the language hid the underlying complexity of data retrieval and file storage mechanisms from the end user.
However, as IBM prepared to formalize and protect the technology, legal complications arose. The acronym SEQUEL was already registered as a trademark by Hawker Siddeley, a British aircraft manufacturing company. To avoid trademark infringement and legal disputes, IBM stripped the word English from the title and shortened the acronym to SQL, representing Structured Query Language.