NPL (for NonProcedural Language) was a
relational database
A relational database is a (most commonly digital) database based on the relational model of data, as proposed by E. F. Codd in 1970. A system used to maintain relational databases is a relational database management system (RDBMS). Many relatio ...
language developed by T.D. Truitt et al.
["An Introduction to Nonprocedural Languages Using NPL", T.D. Truitt et al., McGraw-Hill 1983.][Truitt, T. D. "NPL: the nonprogrammer's data base language" Computer Language 4(06) June 1987 pp97-103] in 1980 for
Apple II
The Apple II (stylized as ) is an 8-bit home computer and one of the world's first highly successful mass-produced microcomputer products. It was designed primarily by Steve Wozniak; Jerry Manock developed the design of Apple II's foam-m ...
and, later, for
MS-DOS
MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...
. In general, a non-procedural language (also called a
declarative language) requires the programmer to specify ''what'' the program should do, rather than (as with a
procedural language
Procedural programming is a programming paradigm, derived from imperative programming, based on the concept of the ''procedure call''. Procedures (a type of routine or subroutine) simply contain a series of computational steps to be carried ...
) providing the sequential steps indicating ''how'' the program should perform its task(s).
Notes and references
Query languages
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