Data query language: Difference between revisions

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{{Short description|Syntax used to query databases}}

{{Distinguish|Query language}}

{{NR|date=June 2023|find="Data query language"}}

'''Data Query Language''' ('''DQL''') is part of the base grouping of [[SQL]] sub-languages. These sub-languages are mainly categorized into four categories, [[Data definition language|DDL]], DQL, [[Data manipulation language|DML]] and [[Data control language|DCL]]. Sometimes [[Transaction Control Language|TCL]] is argued to be part of the sub-language set as well.

'''Data Queryquery Languagelanguage''' ('''DQL''') is part of the base grouping of [[SQL]] sub-languages. These sub-languages are mainly categorized into four categories: a data query language (DQL), a [[Datadata definition language|DDL]], DQL(DDL), a [[Datadata manipulationcontrol language|DML]] (DCL), and a [[Datadata controlmanipulation language|DCL]] (DML). Sometimes [[Transactiona Controltransaction Language|control language (TCL]]) is argued to be part of the sub-language set as well.

DQL statements are used for performing queries on the data within schema objects. The purpose of DQL commands is to get the schema relation based on the query passed to it.

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Although often considered part of DML, the SQL [[Select (SQL)|SELECT]] statement is strictly speaking an example of DQL. When adding FROM or WHERE data manipulators to the SELECT statement the statement is then considered part of the DML.

==Related languageslanguage types==

* [[Data definition language]]

* [[Data manipulation language]]

* [[Data control language]]

* [[Transactional Controlcontrol Languagelanguage]]

==References==

{{Reflist}}

{{Database}}

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[[Category:Data modeling]]

[[Category:SQL]]

[[Category:Database management systems]]