Query language
Encyclopedia
Query languages are computer languages used to make queries into database
s and information system
s.
Broadly, query languages can be classified according to whether they are database query languages or information retrieval query language
s. The difference is that a database query language attempts to give factual answers to factual questions, while an information retrieval query language attempts to find documents containing information that is relevant to an area of inquiry.
Examples include:
Database
A database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
s and information system
Information system
An information system - or application landscape - is any combination of information technology and people's activities that support operations, management, and decision making. In a very broad sense, the term information system is frequently used to refer to the interaction between people,...
s.
Broadly, query languages can be classified according to whether they are database query languages or information retrieval query language
Information retrieval query language
An information retrieval query language is a query language used to make queries into database, where the semantics of the query are defined not by a precise rendering of a formal syntax, but by an interpretation of the most suitable results of the query....
s. The difference is that a database query language attempts to give factual answers to factual questions, while an information retrieval query language attempts to find documents containing information that is relevant to an area of inquiry.
Examples include:
- .QL.QL.QL is an object-oriented query language used to retrieve data from relational database management systems. It is reminiscent of the standard query language SQL and the object-oriented programming language Java. .QL is an object-oriented variant of a logic programming language known in the...
is a proprietary object-oriented query language for querying relational databaseRelational databaseA relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
s; successor of Datalog; - Contextual Query Language (CQL) a formal language for representing queries to information retrievalInformation retrievalInformation retrieval is the area of study concerned with searching for documents, for information within documents, and for metadata about documents, as well as that of searching structured storage, relational databases, and the World Wide Web...
systems such as web indexes or bibliographic catalogues. - CQLF (CODASYL Query Language, Flat) is a query language for CODASYLCODASYLCODASYL is an acronym for "Conference on Data Systems Languages". This was a consortium formed in 1959 to guide the development of a standard programming language that could be used on many computers...
-type databases; - Concept-Oriented Query Language (COQL) is used in the concept-oriented modelConcept-oriented modelThe concept-oriented model is a data model based on the following three principles:* Duality principle postulates that any element consists of two parts, called identity and entity...
(COM). It is based on a novel data modelingData modelingData modeling in software engineering is the process of creating a data model for an information system by applying formal data modeling techniques.- Overview :...
construct, concept, and uses such operations as projection and de-projection for multi-dimensional analysis, analytical operations and inference; - DD (data language specification)D is a set of requirements for what Christopher J. Date and Hugh Darwen believe a relational database query language ought to be like. It is proposed in their book The Third Manifesto.-Overview:...
is a query language for truly relational database management systemsRelational database management systemA relational database management system is a database management system that is based on the relational model as introduced by E. F. Codd. Most popular databases currently in use are based on the relational database model....
(TRDBMS); - DMXData Mining ExtensionsData Mining Extensions is a query language for Data Mining Models supported by Microsoft's SQL Server Analysis Services product.Like SQL, it supports a data definition language, data manipulation language and a data query language, all three with SQL-like syntax.Whereas SQL statements operate on...
is a query language for Data MiningData miningData mining , a relatively young and interdisciplinary field of computer science is the process of discovering new patterns from large data sets involving methods at the intersection of artificial intelligence, machine learning, statistics and database systems...
models; - DatalogDatalogDatalog is a query and rule language for deductive databases that syntactically is a subset of Prolog. Its origins date back to the beginning of logic programming, but it became prominent as a separate area around 1977 when Hervé Gallaire and Jack Minker organized a workshop on logic and databases...
is a query language for deductive databaseDeductive databaseA Deductive database is a database system that can make deductions based on rules and facts stored in the database. Datalog is the language typically used to specify facts, rules and queries in deductive databases...
s; - ERROLERROLERROL is a declarative database query and manipulation language for the Entity-relationship model . It is applicable to any data model on which ERM can be mapped, virtually any general purpose database data model...
is a query language over the Entity-relationship modelEntity-relationship modelIn software engineering, an entity-relationship model is an abstract and conceptual representation of data. Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema or semantic data model of a system, often a relational database, and its requirements...
(ERM) which mimics major Natural languageNatural languageIn the philosophy of language, a natural language is any language which arises in an unpremeditated fashion as the result of the innate facility for language possessed by the human intellect. A natural language is typically used for communication, and may be spoken, signed, or written...
constructs (of the English languageEnglish languageEnglish is a West Germanic language that arose in the Anglo-Saxon kingdoms of England and spread into what was to become south-east Scotland under the influence of the Anglian medieval kingdom of Northumbria...
and possibly other languages). It is especially tailored for relational databaseRelational databaseA relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
s; - Gellish EnglishGellish EnglishGellish English is a variant of Gellish and is a formal language, which means that it is structured and formalised subset of natural English that is computer interpretable. Its definition includes an English dictionary of concepts that is arranged in a taxonomy and that is extended into an ontology...
is a language that can be used for queries in Gellish English Databases, for dialogues (requests and responses) as well as for information modeling and knowledge modelingKnowledge modelingKnowledge modeling is a process of creating a computer interpretable model of knowledge or standard specifications about a kind of process and/or about a kind of facility or product...
; - HTSQLHtsqlHyper Text Structured Query Language is a schema-driven URI-to-SQL query language that takes a request over HTTP, converts it to a SQL query, executes the query against a database, and returns the results in a format best suited for the user agent The HTSQL language is implemented on "HTSQL...
is a query language that translates HTTP queries to SQLSQLSQL is a programming language designed for managing data in relational database management systems ....
; - ISBLISBLISBL is the relational algebra notation that was invented for PRTV, one of the earliest database management systems to implement E.F. Codd's relational model of data.-See also:...
is a query language for PRTVPRTVPRTV was the world's first relational database management system that could handle significant data volumes....
, one of the earliest relational database management systems; - LINQLINQLinq is a word-based card game from Endless Games, introduced at the American International Toy Fair in 2005.Game play requires at least four players, two of whom are dealt cards with the same word, while the others receive blanks. The goal is to gain points by correctly naming the players with...
query-expressions is a way to query various data sources from .NET.NET FrameworkThe .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
languages - LDAP is an application protocol for querying and modifying directory services running over TCP/IP;
- MQLMolecular Query LanguageThe Molecular Query Language was designed to allow more complex, problem-specific search methods in chemoinformatics....
is a cheminformaticsCheminformaticsCheminformatics is the use of computer and informational techniques, applied to a range of problems in the field of chemistry. These in silico techniques are used in pharmaceutical companies in the process of drug discovery...
query language for a substructure search allowing beside nominal properties also numerical properties; - MDXMultidimensional ExpressionsMultidimensional Expressions is a query language for OLAP databases, much like SQL is a query language for relational databases. It is also a calculation language, with syntax similar to spreadsheet formulas.-Background:...
is a query language for OLAPOLAPIn computing, online analytical processing, or OLAP , is an approach to swiftly answer multi-dimensional analytical queries. OLAP is part of the broader category of business intelligence, which also encompasses relational reporting and data mining...
databases; - OQLObject Query LanguageObject Query Language is a query language standard for object-oriented databases modeled after SQL. OQL was developed by the Object Data Management Group . Because of its overall complexity no vendor has ever fully implemented the complete OQL...
is Object Query Language; - OCLObject Constraint LanguageThe Object Constraint Language is a declarative language for describing rules that apply to Unified Modeling Language models developed at IBM and now part of the UML standard. Initially, OCL was only a formal specification language extension to UML. OCL may now be used with any Meta-Object...
(Object Constraint Language). Despite its name, OCL is also an object query language and an OMGObject Management GroupObject Management Group is a consortium, originally aimed at setting standards for distributed object-oriented systems, and is now focused on modeling and model-based standards.- Overview :...
standard; - OPath, intended for use in querying WinFSWinFSWinFS is the code name for a cancelled data storage and management system project based on relational databases, developed by Microsoft and first demonstrated in 2003 as an advanced storage subsystem for the Microsoft Windows operating system, designed for persistence and management of...
Stores; - Poliqarp Query Language is a special query language designed to analyze annotated text. Used in the PoliqarpPoliqarpPoliqarp is an open source search engine designed to process the Polish Corpus created at the Institute of Computer Science, Polish Academy of Sciences.-Features:* Custom query language.* Two-level regular expressions...
search engine; - QUELQUEL query languagesQUEL is a relational database access language, similar in most ways to SQL. It was created as a part of the Ingres effort at University of California, Berkeley, based on Codd's earlier suggested but not implemented Data Sub-Language ALPHA. QUEL was used for a short time in most products based on...
is a relational databaseRelational databaseA relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
access language, similar in most ways to SQLSQLSQL is a programming language designed for managing data in relational database management systems ....
; - RDQL is a RDFResource Description FrameworkThe Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...
query language; - SeRQL ("Sesame RDF Query Language", pronounced "circle") is a new RDF/RDFS query language that is currently being developed by Aduna as part of Sesame.
- SMARTSSmiles arbitrary target specificationSMiles ARbitrary Target Specification is a language for specifying substructural patterns in molecules. The SMARTS line notation is expressive and allows extremely precise and transparent substructural specification and atom typing....
is the cheminformaticsCheminformaticsCheminformatics is the use of computer and informational techniques, applied to a range of problems in the field of chemistry. These in silico techniques are used in pharmaceutical companies in the process of drug discovery...
standard for a substructure search; - SPARQLSPARQLSPARQL is an RDF query language; its name is an acronym that stands for SPARQL Protocol and RDF Query Language. It was made a standard by the RDF Data Access Working Group of the World Wide Web Consortium, and considered as one of the key technologies of semantic web...
is a query language for RDFResource Description FrameworkThe Resource Description Framework is a family of World Wide Web Consortium specifications originally designed as a metadata data model...
graphsGraph (mathematics)In mathematics, a graph is an abstract representation of a set of objects where some pairs of the objects are connected by links. The interconnected objects are represented by mathematical abstractions called vertices, and the links that connect some pairs of vertices are called edges...
; - SQLSQLSQL is a programming language designed for managing data in relational database management systems ....
is a well known query language and Data Manipulation LanguageData Manipulation LanguageA data manipulation language is a family of syntax elements similar to a computer programming language used for inserting, deleting and updating data in a database...
for relational databaseRelational databaseA relational database is a database that conforms to relational model theory. The software used in a relational database is called a relational database management system . Colloquial use of the term "relational database" may refer to the RDBMS software, or the relational database itself...
s; - SuprTool is a proprietary query language for SuprTool, a database access program used for accessing data in Image/SQL (formerly TurboIMAGETurboIMAGEIMAGE is the primary reason that the HP3000 was a success. It is a reliable, simple, fast database for MPE. After about a decade of enhancements it was renamed TurboIMAGE, then TurboIMAGE/XL after the PA-RISC migration...
) and Oracle databases; - TMQL Topic Map Query Language is a query language for Topic Maps;
- UnQLUnQLUnQL is a specification for a query language for NoSQL databases, developed by the creators of SQLite and CouchDB database management systems, based on SQL used in relational databases with the elements of JSON. It is built to query collections of documents with loosely defined fields...
(Unstructured Query Language) is a functional superset of SQL, developed by the authors of SQLiteSQLiteSQLite is an ACID-compliant embedded relational database management system contained in a relatively small C programming library. The source code for SQLite is in the public domain and implements most of the SQL standard...
and CouchDBCouchDBApache CouchDB, commonly referred to as CouchDB, is an open source document-oriented database written mostly in the Erlang programming language. It is part of the NoSQL group of data stores and is designed for local replication and to scale horizontally across a wide range of devices...
; - XQueryXQuery- Features :XQuery provides the means to extract and manipulate data from XML documents or any data source that can be viewed as XML, such as relational databases or office documents....
is a query language for XML data sourcesXML databaseAn XML database is a data persistence software system that allows data to be stored in XML format. This data can then be queried, exported and serialized into the desired format.Two major classes of XML database exist:...
; - XPathXPathXPath is a language for selecting nodes from an XML document. In addition, XPath may be used to compute values from the content of an XML document...
is a declarative language for navigating XML documents; - XSQL is a query language combining the power of XMLXMLExtensible Markup Language is a set of rules for encoding documents in machine-readable form. It is defined in the XML 1.0 Specification produced by the W3C, and several other related specifications, all gratis open standards....
and the power of SQL, it is currently under development; - XSPARQL is an integrated query language combining XQuery with SPARQL to query both XML and RDF data sources at once;
- YQLYahoo! query languageYahoo! query language is an SQL-like query language created by Yahoo! as part of their Developer Network. YQL is designed to retrieve and manipulate data from APIs through a single Web interface, thus allowing mashups that enable developers to create their own applications.Initially launched in...
is an SQLSQLSQL is a programming language designed for managing data in relational database management systems ....
-like query language created by Yahoo!Yahoo!Yahoo! Inc. is an American multinational internet corporation headquartered in Sunnyvale, California, United States. The company is perhaps best known for its web portal, search engine , Yahoo! Directory, Yahoo! Mail, Yahoo! News, Yahoo! Groups, Yahoo! Answers, advertising, online mapping ,...