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, [[DDL]], DQL, [[DML]] and [[DCL]]. Sometimes [[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 [[DDLdata definition language]], DQL(DDL), a [[DMLdata control language]] (DCL), and a [[DCLdata manipulation language]] (DML). Sometimes [[a transaction 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.

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 language types==

=Statements=

* [[Select (SQL)]]

=Related languages=

* [[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]]