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SQL

​SQL (/ˌɛsˌkjuːˈɛl/ (About this soundlisten) S-Q-L,[4] /ˈsiːkwəl/ "sequel"; Structured Query Language)[5] is a domain-specific language used in programming and designed for managing data held in a relational database management system (RDBMS), or for stream processing in a relational data stream management system (RDSMS). It is particularly useful in handling structured data, i.e. data incorporating relations among entities and variables.

SQL offers two main advantages over older read–write APIs such as ISAM or VSAM. Firstly, it introduced the concept of accessing many records with one single command. Secondly, it eliminates the need to specify how to reach a record, e.g. with or without an index.

Originally based upon relational algebra and tuple relational calculus, SQL consists of many types of statements,[6] which may be informally classed as sublanguages, commonly: a data query language (DQL),[a] a data definition language (DDL),[b] a data control language (DCL), and a data manipulation language (DML).[c][7] The scope of SQL includes data query, data manipulation (insert, update and delete), data definition (schema creation and modification), and data access control. Although SQL is essentially a declarative language (4GL), it also includes procedural elements.

SQL was one of the first commercial languages to use Edgar F. Codd’s relational model. The model was described in his influential 1970 paper, "A Relational Model of Data for Large Shared Data Banks".[8] Despite not entirely adhering to the relational model as described by Codd, it became the most widely used database language.[9][10]

SQL became a standard of the American National Standards Institute (ANSI) in 1986, and of the International Organization for Standardization (ISO) in 1987.[11] Since then, the standard has been revised to include a larger set of features. Despite the existence of standards, most SQL code requires at least some changes before being ported to different database systems.

Grantham (/ˈɡrænθəm/ GRAN-thəm) is a market and industrial town in the South Kesteven district of Lincolnshire, England. It straddles the London–Edinburgh East Coast Main Line and the River Witham and is bounded to the west by the A1 north–south trunk road. It lies about 23 miles (37 kilometres) south of the county town, Lincoln, and 22 miles (35 kilometres) east of Nottingham. The population in 2016 was put at 44,580.[1] Grantham is known as the birthplace of former UK Prime Minister Margaret Thatcher, for educating Isaac Newton at the King's School, as the workplace of the UK's first female police officer, Edith Smith in 1914, and for making the UK's first running diesel engine in 1892 and tractor in 1896. Thomas Paine worked there as an excise officer in the 1790s.