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| author | Tom Lane <tgl@sss.pgh.pa.us> | 2024-08-16 12:35:50 -0400 |
|---|---|---|
| committer | Tom Lane <tgl@sss.pgh.pa.us> | 2024-08-16 12:35:53 -0400 |
| commit | 6be39d77a70df52d5a0f2eb414ef9901ccf17e5a (patch) | |
| tree | 53bdc6708c641c016e674635bf87ef601873b77e /doc/src | |
| parent | 108d2adb9e9e084cd57bf514d06ef4b954719ffa (diff) | |
| download | postgresql-6be39d77a70df52d5a0f2eb414ef9901ccf17e5a.tar.gz postgresql-6be39d77a70df52d5a0f2eb414ef9901ccf17e5a.zip | |
Fix extraction of week and quarter fields from intervals.
"EXTRACT(WEEK FROM interval_value)" formerly threw an error.
Define it as "tm->tm_mday / 7". (With C99 division semantics,
this gives consistent results for negative intervals.)
"EXTRACT(QUARTER FROM interval_value)" has been implemented
all along, but it formerly gave extremely strange results for
negative intervals. Fix it so that the output for -N months
is the negative of the output for N months.
Per bug #18348 from Michael Bondarenko and subsequent discussion.
Discussion: https://postgr.es/m/18348-b097a3587dfde8a4@postgresql.org
Diffstat (limited to 'doc/src')
| -rw-r--r-- | doc/src/sgml/func.sgml | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml index 5dd95d73a1a..749360a4b71 100644 --- a/doc/src/sgml/func.sgml +++ b/doc/src/sgml/func.sgml @@ -10432,12 +10432,16 @@ SELECT EXTRACT(MONTH FROM INTERVAL '2 years 13 months'); <term><literal>quarter</literal></term> <listitem> <para> - The quarter of the year (1–4) that the date is in + The quarter of the year (1–4) that the date is in; + for <type>interval</type> values, the month field divided by 3 + plus 1 </para> <screen> SELECT EXTRACT(QUARTER FROM TIMESTAMP '2001-02-16 20:38:40'); <lineannotation>Result: </lineannotation><computeroutput>1</computeroutput> +SELECT EXTRACT(QUARTER FROM INTERVAL '1 year 6 months'); +<lineannotation>Result: </lineannotation><computeroutput>3</computeroutput> </screen> </listitem> </varlistentry> @@ -10508,9 +10512,16 @@ SELECT EXTRACT(SECOND FROM TIME '17:12:28.5'); <literal>week</literal> to get consistent results. </para> + <para> + For <type>interval</type> values, the week field is simply the number + of integral days divided by 7. + </para> + <screen> SELECT EXTRACT(WEEK FROM TIMESTAMP '2001-02-16 20:38:40'); <lineannotation>Result: </lineannotation><computeroutput>7</computeroutput> +SELECT EXTRACT(WEEK FROM INTERVAL '13 days 24 hours'); +<lineannotation>Result: </lineannotation><computeroutput>1</computeroutput> </screen> </listitem> </varlistentry> |