英文字典中文字典


英文字典中文字典51ZiDian.com



中文字典辞典   英文字典 a   b   c   d   e   f   g   h   i   j   k   l   m   n   o   p   q   r   s   t   u   v   w   x   y   z       







请输入英文单字，中文词皆可：

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)


请选择你想看的字典辞典：
单词字典翻译
SQL查看　SQL　在百度字典中的解释百度英翻中〔查看〕
SQL查看　SQL　在Google字典中的解释Google英翻中〔查看〕
SQL查看　SQL　在Yahoo字典中的解释Yahoo英翻中〔查看〕

安装中文字典英文字典查询工具!


中文字典英文字典工具:
选择颜色:
输入中英文单字

































































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, Sybase, Informix, Postgres, and other database systems
  • SQL - Wikipedia
    Structured Query Language (SQL) (pronounced ˌɛsˌkjuˈɛl S-Q-L; or alternatively as ˈsiːkwəl ⓘ "sequel") [4][5] is a domain-specific language used to manage data, especially in a relational database management system (RDBMS)
  • SQL Tutorial - GeeksforGeeks
    In this SQL tutorial, you’ll learn all the basic to advanced SQL concepts like SQL queries, SQL join, SQL injection, SQL insert, and creating tables in SQL SQL's integration with various technologies makes it essential for managing and querying data in databases
  • SQL Tutorial: Learn SQL from Scratch for Beginners
    This SQL Tutorial helps you master SQL quickly and effectively with clear concepts, hands-on examples, and interactive quizzes 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
  • SQL Tutorial - Learn SQL Basics and Advanced Techniques
    Our SQL tutorial helps you learn SQL (Structured Query Language) in simple and easy steps so that you can start your database programming quickly It covers most of the important concepts related to SQL for a basic to advanced understanding of SQL and to get a feel of how SQL works
  • What is a SQL Database? | Microsoft Azure
    SQL databases, also known as relational databases, are systems that store collections of tables and organize structured sets of data in a tabular columns-and-rows format, similar to that of a spreadsheet The databases are built using structured query language (SQL), the query language that not only makes up all relational databases and relational database management systems (RDBMS), but also
  • SQL Easy: The Best Way to Learn SQL (Its FREE!)
    SQL stands for Structured Query Language SQL is used to communicate with a database and SQL 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
  • What Is SQL? - LearnSQL. com
    SQL, or Structured Query Language, is a programming language used to talk to databases With SQL, you can store, manipulate, and retrieve data from relational databases Retrieve data from a database Filter and sort data from a database Perform computations on database data Insert records into a database Update existing records in a database





中文字典-英文字典  2005-2009