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SQL    
结构式查询语言

结构式查询语言

/S Q L/ An industry-standard
language for creating, updating and, querying {relational
database management systems}.

SQL was developed by {IBM} in the 1970s for use in {System R}.
It is the {de facto standard} as well as being an {ISO} and
{ANSI} {standard}. It is often embedded in general purpose
programming languages.

The first SQL standard, in 1986, provided basic language
constructs for defining and manipulating {tables} of data; a
revision in 1989 added language extensions for {referential
integrity} and generalised {integrity} {constraints}. Another
revision in 1992 provided facilities for {schema} manipulation
and {data administration}, as well as substantial enhancements
for data definition and data manipulation.

Development is currently underway to enhance SQL into a
computationally complete language for the definition and
management of {persistent}, complex objects. This includes:
generalisation and specialisation hierarchies, {multiple
inheritance}, user defined {data types}, {triggers} and
{assertions}, support for {knowledge based systems},
{recursive query expressions}, and additional data
administration tools. It also includes the specification of
{abstract data types} (ADTs), object identifiers, {methods},
{inheritance}, {polymorphism}, {encapsulation}, and all of the
other facilities normally associated with object data
management.

The emerging {SQL3} standard is expected to be complete in
1998.

According to Allen G. Taylor, SQL does __not__ stand for
"Structured Query Language". That, like "SEQUEL" (and its
pronunciation /see'kw*l/), was just another unofficial name
for a precursor of SQL. However, the IBM SQL Reference manual
for DB2 and Craig Mullins's "DB2 Developer's Guide" say SQL
__does__ stand for "Structured Query Language".

{SQL Standards (http://jcc.com/sql_stnd.html)}.

{An SQL parser
(ftp://ftp.ora.com/published/oreilly/nutshell/lexyacc/)} is
described in "Lex & Yacc", by Levine, Mason & Brown published
by O'Reilly.

{The 1995 SQL Reunion: People, Projects, and Politics
(http://mcjones.org/System_R/SQL_Reunion_95/)}.

["A Guide to the SQL Standard", C.J. Date, A-W 1987].

["SQL for Dummies", Allen G. Taylor, IDG Books Worldwide].

(2005-11-17)


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英文字典中文字典相关资料:


  • SQL Tutorial - W3Schools
    SQL is a standard language for storing, manipulating and retrieving data in databases Our SQL tutorial will teach you how to use SQL in MySQL, SQL Server, MS Access, Oracle, PostgreSQL, and more
  • SQL - Wikipedia
    Introduced in the 1970s, SQL offered 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, i e , with or without an index
  • SQL Cheat Sheet ( Basic to Advanced) - GeeksforGeeks
    This SQL Cheat Sheet is your quick-reference guide for working with relational databases It helps you recall key commands, logic, and query patterns to manage, manipulate, and control data efficiently
  • SQL Tutorial: Learn SQL from Scratch for Beginners
    Whether you’re a software developer, database administrator, data analyst, or data scientist, this SQL tutorial will help you unlock the power of SQL for managing and analyzing data
  • Microsoft SQL Server downloads
    Get started with Microsoft SQL Server downloads Choose a SQL Server trial, edition, tool, or connector that best meets your data and workload needs
  • What is SQL? - Structured Query Language (SQL) Explained - AWS
    Structured query language (SQL) is a programming language for storing and processing information in a relational database A relational database stores information in tabular form, with rows and columns representing different data attributes and the various relationships between the data values
  • Should I use != or lt; gt; for not equal in T-SQL? - Stack Overflow
    Portability of code If your requirements are easily met by ANSI SQL, then its better to use it You can use the same code in all DB's Eg An SQL book author who wants to illustrate basic SQL using sample code
  • FreeSQL - Oracle
    Write, run, and share real Oracle SQL directly in your browser Learn SQL fundamentals, experiment with real data, and explore community scripts with zero setup and no installation required
  • What is SQL How Does It Work? A Guide to Structured Query Language
    What is SQL And How Does it Work? SQL is the most common language for extracting and organising data that is stored in a relational database A database is a table that consists of rows and columns SQL is the language of databases It facilitates retrieving specific information from databases that are further used for analysis
  • What is Structured Query Language (SQL)? - IBM
    Structured query language (SQL) is a domain-specific, standardized programming language used to interact with relational database management systems (RDBMS)





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