Window function (SQL) - Revision history

Djonesuk: /* History */ add SQLite

2025-02-05T00:25:38Z

History: add SQLite

← Previous revision		Revision as of 00:25, 5 February 2025
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	* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>		* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>
	* [[MariaDB]] - version 10.2 in 2016.<ref>{{Cite web \| title=MariaDB 10.2.0 Release Notes \|url=https://mariadb.com/kb/en/mariadb-1020-release-notes/ \| access-date=2024-03-10 \| website=mariadb.com}}</ref>		* [[MariaDB]] - version 10.2 in 2016.<ref>{{Cite web \| title=MariaDB 10.2.0 Release Notes \|url=https://mariadb.com/kb/en/mariadb-1020-release-notes/ \| access-date=2024-03-10 \| website=mariadb.com}}</ref>
			* [[SQLite]] - release 3.25.0 in 2018.<ref>{{cite web \|title=SQLite Release 3.25.0 On 2018-09-15 \|url=https://www.sqlite.org/releaselog/3_25_0.html \|website=www.sqlite.org \|access-date=5 February 2025}}</ref>

	== See also ==		== See also ==

GoingBatty: /* History */ fixed link

2025-01-24T23:05:38Z

History: fixed link

← Previous revision		Revision as of 23:05, 24 January 2025
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	Support for particular database implementations was added as follows:		Support for particular database implementations was added as follows:

	* [[Oracle]] - version 8.1.6 in 2000.<ref>{{Cite web \| title=Oracle 8i Release 2 (8.1.6) New Features\|url=https://docs.oracle.com/cd/A81042_01/DOC/server.816/a76962/816.htm \| access-date=2025-01-23 \| website=www.oracle.com }}</ref><ref>{{Cite web \| title=Analytic Functions in Oracle 8i\|url=http://infolab.stanford.edu/infoseminar/archive/SpringY2000/speakers/agupta/paper.pdf \| access-date=2025-01-23 \| website=www.stanford.edu }}</ref>		* [[Oracle Database\|Oracle]] - version 8.1.6 in 2000.<ref>{{Cite web \| title=Oracle 8i Release 2 (8.1.6) New Features\|url=https://docs.oracle.com/cd/A81042_01/DOC/server.816/a76962/816.htm \| access-date=2025-01-23 \| website=www.oracle.com }}</ref><ref>{{Cite web \| title=Analytic Functions in Oracle 8i\|url=http://infolab.stanford.edu/infoseminar/archive/SpringY2000/speakers/agupta/paper.pdf \| access-date=2025-01-23 \| website=www.stanford.edu }}</ref>
	* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org\|date=24 July 2014 }}</ref>		* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org\|date=24 July 2014 }}</ref>
	* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>		* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>

Duke Ganote: /* History */ "incorporated into" SQL standard, rather than "introduced in"

2025-01-23T17:41:50Z

History: "incorporated into" SQL standard, rather than "introduced in"

← Previous revision		Revision as of 17:41, 23 January 2025
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	== History ==		== History ==
	Window functions were ~~introduced~~ to the [[SQL:2003]] standard and had functionality expanded in later specifications.<ref>{{Cite web\|title=Window Functions Overview\|url=https://mariadb.com/kb/en/window-functions-overview/\|access-date=2021-03-23\|website=MariaDB KnowledgeBase}}</ref>		Window functions were incorporated into the [[SQL:2003]] standard and had functionality expanded in later specifications.<ref>{{Cite web\|title=Window Functions Overview\|url=https://mariadb.com/kb/en/window-functions-overview/\|access-date=2021-03-23\|website=MariaDB KnowledgeBase}}</ref>

	Support for particular database implementations was added as follows:		Support for particular database implementations was added as follows:

Duke Ganote: /* History */ "analytic... SQL functions are now being reviewed by ANSI for addition to the SQL standard in 2000"

2025-01-23T13:23:15Z

History: "analytic... SQL functions are now being reviewed by ANSI for addition to the SQL standard in 2000"

← Previous revision		Revision as of 13:23, 23 January 2025
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	Support for particular database implementations was added as follows:		Support for particular database implementations was added as follows:

			* [[Oracle]] - version 8.1.6 in 2000.<ref>{{Cite web \| title=Oracle 8i Release 2 (8.1.6) New Features\|url=https://docs.oracle.com/cd/A81042_01/DOC/server.816/a76962/816.htm \| access-date=2025-01-23 \| website=www.oracle.com }}</ref><ref>{{Cite web \| title=Analytic Functions in Oracle 8i\|url=http://infolab.stanford.edu/infoseminar/archive/SpringY2000/speakers/agupta/paper.pdf \| access-date=2025-01-23 \| website=www.stanford.edu }}</ref>
	* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org\|date=24 July 2014 }}</ref>		* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org\|date=24 July 2014 }}</ref>
	* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>		* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>

Citation bot: Altered title. Add: date, authors 1-1. Removed parameters. Some additions/deletions were parameter name changes. | Use this bot. Report bugs. | Suggested by Abductive | Category:SQL | #UCB_Category 23/76

2024-07-26T08:15:28Z

Altered title. Add: date, authors 1-1. Removed parameters. Some additions/deletions were parameter name changes. | Use this bot. Report bugs. | Suggested by Abductive | Category:SQL | #UCB_Category 23/76

← Previous revision		Revision as of 08:15, 26 July 2024
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	== Example ==		== Example ==
	Window functions allow access to data in the records right before and after the current record.<ref>{{Cite journal\|~~last~~=Leis\|~~first~~=Viktor\|last2=Kundhikanjana\|first2=Kan\|last3=Kemper\|first3=Alfons\|last4=Neumann\|first4=Thomas\|date=June 2015\|title=Efficient Processing of Window Functions in Analytical SQL Queries\|journal=Proc. VLDB Endow.\|volume=8\|issue=10\|pages=1058–1069\|doi=10.14778/2794367.2794375\|issn=2150-8097}}</ref><ref>{{Cite journal\|~~last~~=Cao\|~~first~~=Yu\|last2=Chan\|first2=Chee-Yong\|last3=Li\|first3=Jie\|last4=Tan\|first4=Kian-Lee\|date=July 2012\|title=Optimization of Analytic Window Functions\|journal=Proc. VLDB Endow.\|volume=5\|issue=11\|pages=1244–1255\|arxiv=1208.0086\|doi=10.14778/2350229.2350243\|issn=2150-8097}}</ref><ref>{{Cite news\|date=2013-11-03\|title=Probably the Coolest SQL Feature: Window Functions\|language=en-US\|work=Java, SQL and jOOQ.\|url=https://blog.jooq.org/2013/11/03/probably-the-coolest-sql-feature-window-functions/\|access-date=2017-09-26}}</ref><ref>{{Cite news\|date=2013-10-31\|title=Window Functions in SQL - Simple Talk\|language=en-US\|work=Simple Talk\|url=https://www.red-gate.com/simple-talk/sql/t-sql-programming/window-functions-in-sql/\|access-date=2017-09-26}}</ref> A window function defines a ''frame'' or ''window'' of rows with a given length around the current row, and performs a calculation across the set of data in the window.<ref>{{Cite web\|last=\|first=\|date=\|title=SQL Window Functions Introduction\|url=https://drill.apache.org/docs/sql-window-functions-introduction/\|archive-url=\|archive-date=\|access-date=\|website=Apache Drill}}</ref><ref>{{Cite web\|title=PostgreSQL: Documentation: Window Functions\|url=https://www.postgresql.org/docs/current/tutorial-window.html\|access-date=2020-04-04\|website=www.postgresql.org\|language=en}}</ref>		Window functions allow access to data in the records right before and after the current record.<ref>{{Cite journal\|last1=Leis\|first1=Viktor\|last2=Kundhikanjana\|first2=Kan\|last3=Kemper\|first3=Alfons\|last4=Neumann\|first4=Thomas\|date=June 2015\|title=Efficient Processing of Window Functions in Analytical SQL Queries\|journal=Proc. VLDB Endow.\|volume=8\|issue=10\|pages=1058–1069\|doi=10.14778/2794367.2794375\|issn=2150-8097}}</ref><ref>{{Cite journal\|last1=Cao\|first1=Yu\|last2=Chan\|first2=Chee-Yong\|last3=Li\|first3=Jie\|last4=Tan\|first4=Kian-Lee\|date=July 2012\|title=Optimization of Analytic Window Functions\|journal=Proc. VLDB Endow.\|volume=5\|issue=11\|pages=1244–1255\|arxiv=1208.0086\|doi=10.14778/2350229.2350243\|issn=2150-8097}}</ref><ref>{{Cite news\|date=2013-11-03\|title=Probably the Coolest SQL Feature: Window Functions\|language=en-US\|work=Java, SQL and jOOQ.\|url=https://blog.jooq.org/2013/11/03/probably-the-coolest-sql-feature-window-functions/\|access-date=2017-09-26}}</ref><ref>{{Cite news\|date=2013-10-31\|title=Window Functions in SQL - Simple Talk\|language=en-US\|work=Simple Talk\|url=https://www.red-gate.com/simple-talk/sql/t-sql-programming/window-functions-in-sql/\|access-date=2017-09-26}}</ref> A window function defines a ''frame'' or ''window'' of rows with a given length around the current row, and performs a calculation across the set of data in the window.<ref>{{Cite web\|last=\|first=\|date=\|title=SQL Window Functions Introduction\|url=https://drill.apache.org/docs/sql-window-functions-introduction/\|archive-url=\|archive-date=\|access-date=\|website=Apache Drill}}</ref><ref>{{Cite web\|title=PostgreSQL: Documentation: Window Functions\|url=https://www.postgresql.org/docs/current/tutorial-window.html\|access-date=2020-04-04\|website=www.postgresql.org\|language=en}}</ref>
	NAME \|		NAME \|
	------------		------------
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	Support for particular database implementations was added as follows:		Support for particular database implementations was added as follows:

	* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org}}</ref>		* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org\|date=24 July 2014 }}</ref>
	* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: ~~What’s~~ New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>		* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What's New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>
	* [[MariaDB]] - version 10.2 in 2016.<ref>{{Cite web \| title=MariaDB 10.2.0 Release Notes \|url=https://mariadb.com/kb/en/mariadb-1020-release-notes/ \| access-date=2024-03-10 \| website=mariadb.com}}</ref>		* [[MariaDB]] - version 10.2 in 2016.<ref>{{Cite web \| title=MariaDB 10.2.0 Release Notes \|url=https://mariadb.com/kb/en/mariadb-1020-release-notes/ \| access-date=2024-03-10 \| website=mariadb.com}}</ref>

Mindmatrix: tweak

2024-03-10T15:23:20Z

tweak

← Previous revision		Revision as of 15:23, 10 March 2024
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	sales \| 4 \| 4800 \| 4866.6666666666666667		sales \| 4 \| 4800 \| 4866.6666666666666667
	(10 rows)		(10 rows)
	The <code>PARTITION BY</code> clause groups rows into partitions, and the function is applied to each partition separately. If the <code>PARTITION BY</code> clause is omitted (such as ~~if we have~~ an empty <code>OVER()</code> clause), then the entire [[result set]] is treated as a single partition.<ref name=":0">{{Cite web\|date=2021-02-11\|title=4.2. Value Expressions\|url=https://www.postgresql.org/docs/13/sql-expressions.html\|access-date=2021-03-23\|website=PostgreSQL Documentation\|language=en}}</ref> For this query, the average salary reported would be the average taken over all rows.		The <code>PARTITION BY</code> clause groups rows into partitions, and the function is applied to each partition separately. If the <code>PARTITION BY</code> clause is omitted (such as with an empty <code>OVER()</code> clause), then the entire [[result set]] is treated as a single partition.<ref name=":0">{{Cite web\|date=2021-02-11\|title=4.2. Value Expressions\|url=https://www.postgresql.org/docs/13/sql-expressions.html\|access-date=2021-03-23\|website=PostgreSQL Documentation\|language=en}}</ref> For this query, the average salary reported would be the average taken over all rows.

	Window functions are evaluated after aggregation (after the [[Group by (SQL)\|<code>GROUP BY</code>]] clause and non-window aggregate functions, for example).<ref name=":1" />		Window functions are evaluated after aggregation (after the [[Group by (SQL)\|<code>GROUP BY</code>]] clause and non-window aggregate functions, for example).<ref name=":1" />

RegGoodwin: /* History */ Update history section

2024-03-10T12:42:31Z

History: Update history section

← Previous revision		Revision as of 12:42, 10 March 2024
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	== History ==		== History ==
	Window functions were introduced in [[SQL:2003]] and had functionality expanded in later specifications.<ref>{{Cite web\|title=Window Functions Overview\|url=https://mariadb.com/kb/en/window-functions-overview/\|access-date=2021-03-23\|website=MariaDB KnowledgeBase}}</ref>		Window functions were introduced to the [[SQL:2003]] standard and had functionality expanded in later specifications.<ref>{{Cite web\|title=Window Functions Overview\|url=https://mariadb.com/kb/en/window-functions-overview/\|access-date=2021-03-23\|website=MariaDB KnowledgeBase}}</ref>

			Support for particular database implementations was added as follows:
⚫	[[MySQL]] ~~added support for window functions in~~ version 8 in 2018~~, and [[MariaDB]] introduced first window functions with version 10.2~~.<ref>{{Cite web \|title=MySQL :: What’s New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>

			* [[PostgreSQL]] - version 8.4 in 2009.<ref>{{Cite web \| title=PostgreSQL Release 8.4 \|url=https://www.postgresql.org/docs/8.4/release-8-4.html \| access-date=2024-03-10 \| website=www.postgresql.org}}</ref>
		⚫	* [[MySQL]] - version 8 in 2018.<ref>{{Cite web \|title=MySQL :: What’s New in MySQL 8.0? (Generally Available) \|url=https://dev.mysql.com/blog-archive/whats-new-in-mysql-8-0-generally-available/ \|access-date=2022-11-21 \|website=dev.mysql.com}}</ref><ref>{{Cite web \|title=MySQL :: MySQL 8.0 Reference Manual :: 12.21.2 Window Function Concepts and Syntax \|url=https://dev.mysql.com/doc/refman/8.0/en/window-functions-usage.html \|website=dev.mysql.com}}</ref>
			* [[MariaDB]] - version 10.2 in 2016.<ref>{{Cite web \| title=MariaDB 10.2.0 Release Notes \|url=https://mariadb.com/kb/en/mariadb-1020-release-notes/ \| access-date=2024-03-10 \| website=mariadb.com}}</ref>

	== See also ==		== See also ==

AugPi: /* See also */ §

2024-01-08T02:41:54Z

AugPi: /* Example */ AUX

2024-01-08T02:32:22Z

Example: AUX

← Previous revision		Revision as of 02:32, 8 January 2024
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	sales \| 4 \| 4800 \| 4866.6666666666666667		sales \| 4 \| 4800 \| 4866.6666666666666667
	(10 rows)		(10 rows)
	The <code>PARTITION BY</code> clause groups rows into partitions, and the function is applied to each partition separately. If the <code>PARTITION BY</code> clause is omitted (such as if we have an empty <code>OVER()</code> clause), then the entire [[result set]] treated as a single partition.<ref name=":0">{{Cite web\|date=2021-02-11\|title=4.2. Value Expressions\|url=https://www.postgresql.org/docs/13/sql-expressions.html\|access-date=2021-03-23\|website=PostgreSQL Documentation\|language=en}}</ref> For this query, the average salary reported would be the average taken over all rows.		The <code>PARTITION BY</code> clause groups rows into partitions, and the function is applied to each partition separately. If the <code>PARTITION BY</code> clause is omitted (such as if we have an empty <code>OVER()</code> clause), then the entire [[result set]] is treated as a single partition.<ref name=":0">{{Cite web\|date=2021-02-11\|title=4.2. Value Expressions\|url=https://www.postgresql.org/docs/13/sql-expressions.html\|access-date=2021-03-23\|website=PostgreSQL Documentation\|language=en}}</ref> For this query, the average salary reported would be the average taken over all rows.

	Window functions are evaluated after aggregation (after the [[Group by (SQL)\|<code>GROUP BY</code>]] clause and non-window aggregate functions, for example).<ref name=":1" />		Window functions are evaluated after aggregation (after the [[Group by (SQL)\|<code>GROUP BY</code>]] clause and non-window aggregate functions, for example).<ref name=":1" />

18.10.88.149: link DSP window function

2023-05-01T15:43:00Z

link DSP window function

← Previous revision		Revision as of 15:43, 1 May 2023
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	{{Short description\|Function over multiple rows in SQL}}		{{Short description\|Function over multiple rows in SQL}}
			{{For\|the term used in signal processing\|Window function}}

	In [[SQL]], a '''window function''' or '''analytic function'''<ref name=":1">{{Cite web\|title=Analytic function concepts in Standard SQL {{!}} BigQuery\|url=https://cloud.google.com/bigquery/docs/reference/standard-sql/analytic-function-concepts\|access-date=2021-03-23\|website=Google Cloud\|language=en}}</ref> is a function which uses values from one or multiple [[Row (database)\|rows]] to return a value for each row. (This contrasts with an [[aggregate function]], which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather an aggregate or single-row (scalar) function.<ref>{{Cite web\|title=Window Functions\|url=https://sqlite.org/windowfunctions.html\|access-date=2021-03-23\|website=sqlite.org}}</ref>		In [[SQL]], a '''window function''' or '''analytic function'''<ref name=":1">{{Cite web\|title=Analytic function concepts in Standard SQL {{!}} BigQuery\|url=https://cloud.google.com/bigquery/docs/reference/standard-sql/analytic-function-concepts\|access-date=2021-03-23\|website=Google Cloud\|language=en}}</ref> is a function which uses values from one or multiple [[Row (database)\|rows]] to return a value for each row. (This contrasts with an [[aggregate function]], which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather an aggregate or single-row (scalar) function.<ref>{{Cite web\|title=Window Functions\|url=https://sqlite.org/windowfunctions.html\|access-date=2021-03-23\|website=sqlite.org}}</ref>

← Previous revision		Revision as of 02:41, 8 January 2024
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	== See also ==		== See also ==

	* [[Select (SQL)#Limiting result rows]]		* [[Select (SQL)#Limiting result rows\|Select (SQL) § Limiting result rows]]

	== References ==		== References ==

← Previous revision		Revision as of 15:43, 1 May 2023
Line 1:		Line 1:
	{{Short description\|Function over multiple rows in SQL}}		{{Short description\|Function over multiple rows in SQL}}
			{{For\|the term used in signal processing\|Window function}}

	In [[SQL]], a '''window function''' or '''analytic function'''<ref name=":1">{{Cite web\|title=Analytic function concepts in Standard SQL {{!}} BigQuery\|url=https://cloud.google.com/bigquery/docs/reference/standard-sql/analytic-function-concepts\|access-date=2021-03-23\|website=Google Cloud\|language=en}}</ref> is a function which uses values from one or multiple [[Row (database)\|rows]] to return a value for each row. (This contrasts with an [[aggregate function]], which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather an aggregate or single-row (scalar) function.<ref>{{Cite web\|title=Window Functions\|url=https://sqlite.org/windowfunctions.html\|access-date=2021-03-23\|website=sqlite.org}}</ref>		In [[SQL]], a '''window function''' or '''analytic function'''<ref name=":1">{{Cite web\|title=Analytic function concepts in Standard SQL {{!}} BigQuery\|url=https://cloud.google.com/bigquery/docs/reference/standard-sql/analytic-function-concepts\|access-date=2021-03-23\|website=Google Cloud\|language=en}}</ref> is a function which uses values from one or multiple [[Row (database)\|rows]] to return a value for each row. (This contrasts with an [[aggregate function]], which returns a single value for multiple rows.) Window functions have an OVER clause; any function without an OVER clause is not a window function, but rather an aggregate or single-row (scalar) function.<ref>{{Cite web\|title=Window Functions\|url=https://sqlite.org/windowfunctions.html\|access-date=2021-03-23\|website=sqlite.org}}</ref>