diff options
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 48 |
1 files changed, 38 insertions, 10 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 47727a1f412..d168891d4e7 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -1,4 +1,4 @@ -<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.435 2008/05/04 21:13:35 tgl Exp $ --> +<!-- $PostgreSQL: pgsql/doc/src/sgml/func.sgml,v 1.436 2008/05/04 23:19:23 tgl Exp $ --> <chapter id="functions"> <title>Functions and Operators</title> @@ -10650,6 +10650,16 @@ AND </entry> </row> + <row> + <entry><literal><function>generate_series</function>(<parameter>start</parameter>, <parameter>stop</parameter>, <parameter>step</parameter> <type>interval</>)</literal></entry> + <entry><type>timestamp</type> or <type>timestamp with time zone</type></entry> + <entry><type>setof timestamp</type> or <type>setof timestamp with time zone</type> (same as argument type)</entry> + <entry> + Generate a series of values, from <parameter>start</parameter> to <parameter>stop</parameter> + with a step size of <parameter>step</parameter> + </entry> + </row> + </tbody> </tgroup> </table> @@ -10683,6 +10693,7 @@ select * from generate_series(4,3); ----------------- (0 rows) +-- this example relies on the date-plus-integer operator select current_date + s.a as dates from generate_series(0,14,7) as s(a); dates ------------ @@ -10690,16 +10701,26 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a); 2004-02-12 2004-02-19 (3 rows) + +select * from generate_series('2008-03-01 00:00'::timestamp, + '2008-03-04 12:00', '10 hours'); + generate_series +--------------------- + 2008-03-01 00:00:00 + 2008-03-01 10:00:00 + 2008-03-01 20:00:00 + 2008-03-02 06:00:00 + 2008-03-02 16:00:00 + 2008-03-03 02:00:00 + 2008-03-03 12:00:00 + 2008-03-03 22:00:00 + 2008-03-04 08:00:00 +(9 rows) </programlisting> </para> <table id="functions-srf-subscripts"> - - <indexterm> - <primary>generate_subscripts</primary> - </indexterm> - - <title>Subscripts Generating Functions</title> + <title>Subscript Generating Functions</title> <tgroup cols="3"> <thead> <row> @@ -10711,7 +10732,7 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a); <tbody> <row> - <entry><literal><function>generate_subscripts</function>(<parameter>array annyarray</parameter>, <parameter>dim int</parameter>)</literal></entry> + <entry><literal><function>generate_subscripts</function>(<parameter>array anyarray</parameter>, <parameter>dim int</parameter>)</literal></entry> <entry><type>setof int</type></entry> <entry> Generate a series comprising the given array's subscripts. @@ -10719,7 +10740,7 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a); </row> <row> - <entry><literal><function>generate_subscripts</function>(<parameter>array annyarray</parameter>, <parameter>dim int</parameter>, <parameter>reverse boolean</parameter>)</literal></entry> + <entry><literal><function>generate_subscripts</function>(<parameter>array anyarray</parameter>, <parameter>dim int</parameter>, <parameter>reverse boolean</parameter>)</literal></entry> <entry><type>setof int</type></entry> <entry> Generate a series comprising the given array's subscripts. When @@ -10732,10 +10753,17 @@ select current_date + s.a as dates from generate_series(0,14,7) as s(a); </tgroup> </table> + <indexterm> + <primary>generate_subscripts</primary> + </indexterm> + <para> + <function>generate_subscripts</> is a convenience function that generates + the set of valid subscripts for the specified dimension of the given + array. Zero rows are returned for arrays that do not have the requested dimension, or for NULL arrays (but valid subscripts are returned for NULL array - elements.) Some examples follow: + elements). Some examples follow: <programlisting> -- basic usage select generate_subscripts('{NULL,1,NULL,2}'::int[], 1) as s; |