<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >Set Returning Functions</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REV="MADE" HREF="mailto:pgsql-docs@postgresql.org"><LINK REL="HOME" TITLE="PostgreSQL 8.0.11 Documentation" HREF="index.html"><LINK REL="UP" TITLE="Functions and Operators" HREF="functions.html"><LINK REL="PREVIOUS" TITLE="Row and Array Comparisons" HREF="functions-comparisons.html"><LINK REL="NEXT" TITLE="System Information Functions" HREF="functions-info.html"><LINK REL="STYLESHEET" TYPE="text/css" HREF="stylesheet.css"><META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=ISO-8859-1"><META NAME="creation" CONTENT="2007-02-02T03:57:22"></HEAD ><BODY CLASS="SECT1" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="5" ALIGN="center" VALIGN="bottom" >PostgreSQL 8.0.11 Documentation</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="functions-comparisons.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="10%" ALIGN="left" VALIGN="top" ><A HREF="functions.html" >Fast Backward</A ></TD ><TD WIDTH="60%" ALIGN="center" VALIGN="bottom" >Chapter 9. Functions and Operators</TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="functions.html" >Fast Forward</A ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="top" ><A HREF="functions-info.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><DIV CLASS="SECT1" ><H1 CLASS="SECT1" ><A NAME="FUNCTIONS-SRF" >9.18. Set Returning Functions</A ></H1 ><A NAME="AEN12835" ></A ><P > This section describes functions that possibly return more than one row. Currently the only functions in this class are series generating functions, as detailed in <A HREF="functions-srf.html#FUNCTIONS-SRF-SERIES" >Table 9-38</A >. </P ><DIV CLASS="TABLE" ><A NAME="FUNCTIONS-SRF-SERIES" ></A ><P ><B >Table 9-38. Series Generating Functions</B ></P ><TABLE BORDER="1" CLASS="CALSTABLE" ><COL><COL><COL><COL><THEAD ><TR ><TH >Function</TH ><TH >Argument Type</TH ><TH >Return Type</TH ><TH >Description</TH ></TR ></THEAD ><TBODY ><TR ><TD ><TT CLASS="LITERAL" ><CODE CLASS="FUNCTION" >generate_series</CODE >(<TT CLASS="PARAMETER" >start</TT >, <TT CLASS="PARAMETER" >stop</TT >)</TT ></TD ><TD ><TT CLASS="TYPE" >int</TT > or <TT CLASS="TYPE" >bigint</TT ></TD ><TD ><TT CLASS="TYPE" >setof int</TT > or <TT CLASS="TYPE" >setof bigint</TT > (same as argument type)</TD ><TD > Generate a series of values, from <TT CLASS="PARAMETER" >start</TT > to <TT CLASS="PARAMETER" >stop</TT > with a step size of one. </TD ></TR ><TR ><TD ><TT CLASS="LITERAL" ><CODE CLASS="FUNCTION" >generate_series</CODE >(<TT CLASS="PARAMETER" >start</TT >, <TT CLASS="PARAMETER" >stop</TT >, <TT CLASS="PARAMETER" >step</TT >)</TT ></TD ><TD ><TT CLASS="TYPE" >int</TT > or <TT CLASS="TYPE" >bigint</TT ></TD ><TD ><TT CLASS="TYPE" >setof int</TT > or <TT CLASS="TYPE" >setof bigint</TT > (same as argument type)</TD ><TD > Generate a series of values, from <TT CLASS="PARAMETER" >start</TT > to <TT CLASS="PARAMETER" >stop</TT > with a step size of <TT CLASS="PARAMETER" >step</TT >. </TD ></TR ></TBODY ></TABLE ></DIV ><P > When <TT CLASS="PARAMETER" >step</TT > is positive, zero rows are returned if <TT CLASS="PARAMETER" >start</TT > is greater than <TT CLASS="PARAMETER" >stop</TT >. Conversely, when <TT CLASS="PARAMETER" >step</TT > is negative, zero rows are returned if <TT CLASS="PARAMETER" >start</TT > is less than <TT CLASS="PARAMETER" >stop</TT >. Zero rows are also returned for <TT CLASS="LITERAL" >NULL</TT > inputs. It is an error for <TT CLASS="PARAMETER" >step</TT > to be zero. Some examples follow: </P><PRE CLASS="PROGRAMLISTING" >select * from generate_series(2,4); generate_series ----------------- 2 3 4 (3 rows) select * from generate_series(5,1,-2); generate_series ----------------- 5 3 1 (3 rows) select * from generate_series(4,3); generate_series ----------------- (0 rows) select current_date + s.a as dates from generate_series(0,14,7) as s(a); dates ------------ 2004-02-05 2004-02-12 2004-02-19 (3 rows)</PRE ><P> </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="functions-comparisons.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="functions-info.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >Row and Array Comparisons</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="functions.html" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >System Information Functions</TD ></TR ></TABLE ></DIV ></BODY ></HTML >