SQL Data Base
Structured Query Language
Quick overview
Paradigm : Multi-paradigm:
declarative
Family : Programming language
Designed by : Donald D. Chamberlin
Raymond F. Boyce
Developer : ISO/IEC
First appeared : 1974; 43 years ago
Typing discipline : Static, strong
OS : Cross-platform
File formats File format details
Filename extension : .sql
Internet media type : application/sql
Developed by : ISO/IEC
Initial release : 1986
Latest release : SQL:2016
(December 2016; 8 months ago)
Type of format : Database
Standard : ISO/IEC 9075
Open format ? Yes
SQL (pronounced "ess-que-el") stands for Structured Query Language.
SQL is used to communicate with a database.According to ANSI (American National Standards Institute),it is the standard language for relational database management systems.SQL statements are used to perform tasks such as update data on a database, or retrieve data from a database.
Some common relational database management systems that use SQL are: Oracle, Sybase, Microsoft SQL Server, Access, Ingres,etc.Although most database systems use SQL, most of them also have their own additional proprietary extensions that are usually only used on their system.However, the standard SQL commands such as "Select", "Insert", "Update", "Delete", "Create", and "Drop" can be used to accomplish almost everything that one needs to do with a database.
History:-
SQL was initially developed at IBM by Donald D. Chamberlin and Raymond F.
Boyce in the early 1970s.This version, initially called SEQUEL (Structured English Query Language), was designed to manipulate and retrieve data stored in IBM's original quasi-relational database management system, System R, which a group at IBM San Jose Research Laboratory had developed during the 1970s.
The acronym SEQUEL was later changed to SQL because "SEQUEL" was a trademark of the UK-based Hawker Siddeley aircraft company.
In the late 1970s, Relational Software, Inc. (now Oracle Corporation) saw the potential of the concepts described by Codd, Chamberlin, and Boyce, and developed their own SQL-based RDBMS with aspirations of selling it to the U.S. Navy, Central Intelligence Agency,and other U.S. government agencies.
In June 1979, Relational Software, Inc. introduced the first commercially available implementation of SQL, Oracle V2 (Version2) for VAX computers.
After testing SQL at customer test sites to determine the usefulness and practicality of the system, IBM began developing commercial products based on their System R prototype including System/38, SQL/DS, and DB2, which were commercially available in 1979, 1981, and 1983, respectively.
Design :-
SQL deviates in several ways from its theoretical foundation, the relational model and its tuple calculus.
In that model, a table is a set of tuples, while in SQL, tables and query results are lists of rows : the same row may occur multiple times, and the order of rows can be employed in queries (e.g. in the LIMIT clause).
Critics argue that SQL should be replaced with a language that strictly returns to the original foundation.
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#SQL NOTES :- Downlode notes 2
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