OSDN Git Service

Add a new GUC variable called "IntervalStyle" that decouples interval output
authorTom Lane <tgl@sss.pgh.pa.us>
Sun, 9 Nov 2008 00:28:35 +0000 (00:28 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Sun, 9 Nov 2008 00:28:35 +0000 (00:28 +0000)
from DateStyle, and create a new interval style that produces output matching
the SQL standard (at least for interval values that fall within the standard's
restrictions).  IntervalStyle is also used to resolve the conflict between the
standard and traditional Postgres rules for interpreting negative interval
input.

Ron Mayer

18 files changed:
doc/src/sgml/config.sgml
doc/src/sgml/datatype.sgml
doc/src/sgml/libpq.sgml
doc/src/sgml/protocol.sgml
doc/src/sgml/ref/copy.sgml
src/backend/utils/adt/datetime.c
src/backend/utils/adt/nabstime.c
src/backend/utils/adt/timestamp.c
src/backend/utils/init/globals.c
src/backend/utils/misc/guc.c
src/backend/utils/misc/postgresql.conf.sample
src/bin/pg_dump/pg_dump.c
src/bin/psql/tab-complete.c
src/include/miscadmin.h
src/interfaces/libpq/fe-connect.c
src/test/regress/expected/interval.out
src/test/regress/pg_regress.c
src/test/regress/sql/interval.sql

index a90009e..715eb44 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.193 2008/11/04 22:40:40 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/config.sgml,v 1.194 2008/11/09 00:28:34 tgl Exp $ -->
 
 <chapter Id="runtime-config">
   <title>Server Configuration</title>
@@ -4014,6 +4014,33 @@ SET XML OPTION { DOCUMENT | CONTENT };
       </listitem>
      </varlistentry>
 
+     <varlistentry id="guc-intervalstyle" xreflabel="IntervalStyle">
+      <term><varname>IntervalStyle</varname> (<type>string</type>)</term>
+      <indexterm>
+       <primary><varname>IntervalStyle</> configuration parameter</primary>
+      </indexterm>
+      <listitem>
+       <para>
+        Sets the display format for interval values.
+        The value <literal>sql_standard</> will produce
+        output matching <acronym>SQL</acronym> standard interval literals.
+        The value <literal>postgres</> (which is the default) will produce
+        output matching <productname>PostgreSQL</> releases prior to 8.4
+        when the <xref linkend="guc-datestyle">
+        parameter was set to <literal>ISO</>.
+        The value <literal>postgres_verbose</> will produce output
+        matching <productname>PostgreSQL</> releases prior to 8.4
+        when the <varname>DateStyle</>
+        parameter was set to non-<literal>ISO</> output.
+       </para>
+       <para>
+        The <varname>IntervalStyle</> parameter also affects the
+        interpretation of ambiguous interval input.  See
+        <xref linkend="datatype-interval-input"> for more information.
+       </para>
+      </listitem>
+     </varlistentry>
+
      <varlistentry id="guc-timezone" xreflabel="timezone">
       <term><varname>timezone</varname> (<type>string</type>)</term>
       <indexterm>
index d3d2bb5..10da67e 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.231 2008/11/03 22:14:40 petere Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/datatype.sgml,v 1.232 2008/11/09 00:28:34 tgl Exp $ -->
 
  <chapter id="datatype">
   <title id="datatype-title">Data Types</title>
@@ -1420,14 +1420,6 @@ SELECT b, char_length(b) FROM test2;
         <entry>1 microsecond / 14 digits</entry>
        </row>
        <row>
-        <entry><type>interval [ <replaceable>fields</replaceable> ] [ (<replaceable>p</replaceable>) ]</type></entry>
-        <entry>12 bytes</entry>
-        <entry>time intervals</entry>
-        <entry>-178000000 years</entry>
-        <entry>178000000 years</entry>
-        <entry>1 microsecond / 14 digits</entry>
-       </row>
-       <row>
         <entry><type>date</type></entry>
         <entry>4 bytes</entry>
         <entry>dates only</entry>
@@ -1451,6 +1443,14 @@ SELECT b, char_length(b) FROM test2;
         <entry>24:00:00-1459</entry>
         <entry>1 microsecond / 14 digits</entry>
        </row>
+       <row>
+        <entry><type>interval [ <replaceable>fields</replaceable> ] [ (<replaceable>p</replaceable>) ]</type></entry>
+        <entry>12 bytes</entry>
+        <entry>time intervals</entry>
+        <entry>-178000000 years</entry>
+        <entry>178000000 years</entry>
+        <entry>1 microsecond / 14 digits</entry>
+       </row>
       </tbody>
      </tgroup>
     </table>
@@ -1929,65 +1929,6 @@ January 8 04:05:06 1999 PST
     </sect3>
 
     <sect3>
-     <title>Intervals</title>
-
-     <indexterm>
-      <primary>interval</primary>
-     </indexterm>
-
-      <para>
-       <type>interval</type> values can be written with the following syntax:
-
-<programlisting>
-<optional>@</> <replaceable>quantity</> <replaceable>unit</> <optional><replaceable>quantity</> <replaceable>unit</>...</> <optional><replaceable>direction</></optional>
-</programlisting>
-
-      Where: <replaceable>quantity</> is a number (possibly signed);
-      <replaceable>unit</> is <literal>microsecond</literal>,
-      <literal>millisecond</literal>, <literal>second</literal>,
-      <literal>minute</literal>, <literal>hour</literal>, <literal>day</literal>,
-      <literal>week</literal>, <literal>month</literal>, <literal>year</literal>,
-      <literal>decade</literal>, <literal>century</literal>, <literal>millennium</literal>,
-      or abbreviations or plurals of these units;
-      <replaceable>direction</> can be <literal>ago</literal> or
-      empty.  The at sign (<literal>@</>) is optional noise.  The amounts
-      of different units are implicitly added up with appropriate
-      sign accounting.  <literal>ago</literal> negates all the fields.
-     </para>
-
-     <para>
-      Quantities of days, hours, minutes, and seconds can be specified without
-      explicit unit markings.  For example, <literal>'1 12:59:10'</> is read
-      the same as <literal>'1 day 12 hours 59 min 10 sec'</>.  Also,
-      a combination of years and months can be specified with a dash;
-      for example <literal>'200-10'</> is read the same as <literal>'200 years
-      10 months'</>.  (These shorter forms are in fact the only ones allowed
-      by the SQL standard.)
-     </para>
-
-     <para>
-      When writing an interval constant with a <replaceable>fields</>
-      specification, or when assigning to an interval column that was defined
-      with a <replaceable>fields</> specification, the interpretation of
-      unmarked quantities depends on the <replaceable>fields</>.  For
-      example <literal>INTERVAL '1' YEAR</> is read as 1 year, whereas
-      <literal>INTERVAL '1'</> means 1 second.
-     </para>
-
-     <para>
-      Internally <type>interval</> values are stored as months, days,
-      and seconds. This is done because the number of days in a month
-      varies, and a day can have 23 or 25 hours if a daylight savings
-      time adjustment is involved. Because intervals are usually created
-      from constant strings or <type>timestamp</> subtraction, this
-      storage method works well in most cases. Functions
-      <function>justify_days</> and <function>justify_hours</> are
-      available for adjusting days and hours that overflow their normal
-      periods.
-     </para>
-    </sect3>
-
-    <sect3>
      <title>Special Values</title>
 
      <indexterm>
@@ -2190,18 +2131,6 @@ January 8 04:05:06 1999 PST
      </table>
 
     <para>
-     <type>interval</type> output looks like the input format, except
-     that units like <literal>century</literal> or
-     <literal>week</literal> are converted to years and days and
-     <literal>ago</literal> is converted to an appropriate sign.  In
-     ISO mode the output looks like:
-
-<programlisting>
-<optional> <replaceable>quantity</> <replaceable>unit</> <optional> ... </> </> <optional> <replaceable>days</> </> <optional> <replaceable>hours</>:<replaceable>minutes</>:<replaceable>seconds</> </optional>
-</programlisting>
-    </para>
-
-    <para>
      The date/time styles can be selected by the user using the
      <command>SET datestyle</command> command, the <xref
      linkend="guc-datestyle"> parameter in the
@@ -2209,7 +2138,7 @@ January 8 04:05:06 1999 PST
      <envar>PGDATESTYLE</envar> environment variable on the server or
      client.  The formatting function <function>to_char</function>
      (see <xref linkend="functions-formatting">) is also available as
-     a more flexible way to format the date/time output.
+     a more flexible way to format date/time output.
     </para>
    </sect2>
 
@@ -2413,6 +2342,163 @@ January 8 04:05:06 1999 PST
     </para>
    </sect2>
 
+   <sect2 id="datatype-interval-input">
+    <title>Interval Input</title>
+
+    <indexterm>
+     <primary>interval</primary>
+    </indexterm>
+
+     <para>
+      <type>interval</type> values can be written with the following
+      verbose syntax:
+
+<programlisting>
+<optional>@</> <replaceable>quantity</> <replaceable>unit</> <optional><replaceable>quantity</> <replaceable>unit</>...</> <optional><replaceable>direction</></optional>
+</programlisting>
+
+     where <replaceable>quantity</> is a number (possibly signed);
+     <replaceable>unit</> is <literal>microsecond</literal>,
+     <literal>millisecond</literal>, <literal>second</literal>,
+     <literal>minute</literal>, <literal>hour</literal>, <literal>day</literal>,
+     <literal>week</literal>, <literal>month</literal>, <literal>year</literal>,
+     <literal>decade</literal>, <literal>century</literal>, <literal>millennium</literal>,
+     or abbreviations or plurals of these units;
+     <replaceable>direction</> can be <literal>ago</literal> or
+     empty.  The at sign (<literal>@</>) is optional noise.  The amounts
+     of different units are implicitly added up with appropriate
+     sign accounting.  <literal>ago</literal> negates all the fields.
+     This syntax is also used for interval output, if
+     <xref linkend="guc-intervalstyle"> is set to
+     <literal>postgres_verbose</>.
+    </para>
+
+    <para>
+     Quantities of days, hours, minutes, and seconds can be specified without
+     explicit unit markings.  For example, <literal>'1 12:59:10'</> is read
+     the same as <literal>'1 day 12 hours 59 min 10 sec'</>.  Also,
+     a combination of years and months can be specified with a dash;
+     for example <literal>'200-10'</> is read the same as <literal>'200 years
+     10 months'</>.  (These shorter forms are in fact the only ones allowed
+     by the <acronym>SQL</acronym> standard, and are used for output when
+     <varname>IntervalStyle</> is set to <literal>sql_standard</literal>.)
+    </para>
+
+    <para>
+     When writing an interval constant with a <replaceable>fields</>
+     specification, or when assigning to an interval column that was defined
+     with a <replaceable>fields</> specification, the interpretation of
+     unmarked quantities depends on the <replaceable>fields</>.  For
+     example <literal>INTERVAL '1' YEAR</> is read as 1 year, whereas
+     <literal>INTERVAL '1'</> means 1 second.
+    </para>
+
+    <para>
+     According to the <acronym>SQL</> standard all fields of an interval
+     value must have the same sign, so a leading negative sign applies to all
+     fields; for example the negative sign in the interval literal
+     <literal>'-1 2:03:04'</> applies to both the days and hour/minute/second
+     parts.  <productname>PostgreSQL</> allows the fields to have different
+     signs, and traditionally treats each field in the textual representation
+     as independently signed, so that the hour/minute/second part is
+     considered positive in this example.  If <varname>IntervalStyle</> is
+     set to <literal>sql_standard</literal> then a leading sign is considered
+     to apply to all fields (but only if no additional signs appear).
+     Otherwise the traditional <productname>PostgreSQL</> interpretation is
+     used.  To avoid ambiguity, it's recommended to attach an explicit sign
+     to each field if any field is negative.
+    </para>
+
+    <para>
+     Internally <type>interval</> values are stored as months, days,
+     and seconds. This is done because the number of days in a month
+     varies, and a day can have 23 or 25 hours if a daylight savings
+     time adjustment is involved. Because intervals are usually created
+     from constant strings or <type>timestamp</> subtraction, this
+     storage method works well in most cases. Functions
+     <function>justify_days</> and <function>justify_hours</> are
+     available for adjusting days and hours that overflow their normal
+     ranges.
+    </para>
+   </sect2>
+
+   <sect2 id="datatype-interval-output">
+    <title>Interval Output</title>
+
+    <indexterm>
+     <primary>interval</primary>
+     <secondary>output format</secondary>
+     <seealso>formatting</seealso>
+    </indexterm>
+
+    <para>
+     The output format of the interval type can be set to one of the
+     three styles <literal>sql_standard</>,
+     <literal>postgres</>, or <literal>postgres_verbose</>,
+     using the command <literal>SET intervalstyle</literal>.
+     The default is the <literal>postgres</> format.
+     <xref linkend="interval-style-output-table"> shows examples of each
+     output style.
+    </para>
+
+    <para>
+     The <literal>sql_standard</> style produces output that conforms to
+     the SQL standard's specification for interval literal strings, if
+     the interval value meets the standard's restrictions (either year-month
+     only or day-time only, with no mixing of positive
+     and negative components).  Otherwise the output looks like a standard
+     year-month literal string followed by a day-time literal string,
+     with explicit signs added to disambiguate mixed-sign intervals.
+    </para>
+
+    <para>
+     The output of the <literal>postgres</> style matches the output of
+     <productname>PostgreSQL</> releases prior to 8.4 when the
+     <xref linkend="guc-datestyle"> parameter was set to <literal>ISO</>.
+    </para>
+
+    <para>
+     The output of the <literal>postgres_verbose</> style matches the output of
+     <productname>PostgreSQL</> releases prior to 8.4 when the
+     <varname>DateStyle</> parameter was set to non-<literal>ISO</> output.
+    </para>
+
+     <table id="interval-style-output-table">
+       <title>Interval Output Style Examples</title>
+       <tgroup cols="4">
+        <thead>
+         <row>
+          <entry>Style Specification</entry>
+          <entry>Year-Month Interval</entry>
+          <entry>Day-Time Interval</entry>
+          <entry>Mixed Interval</entry>
+         </row>
+        </thead>
+        <tbody>
+         <row>
+          <entry><literal>sql_standard</></entry>
+          <entry>1-2</entry>
+          <entry>3 4:05:06</entry>
+          <entry>-1-2 +3 -4:05:06</entry>
+         </row>
+         <row>
+          <entry><literal>postgres</></entry>
+          <entry>1 year 2 mons</entry>
+          <entry>3 days 04:05:06</entry>
+          <entry>-1 year -2 mons +3 days -04:05:06</entry>
+         </row>
+         <row>
+          <entry><literal>postgres_verbose</></entry>
+          <entry>@ 1 year 2 mons</entry>
+          <entry>@ 3 days 4 hours 5 mins 6 secs</entry>
+          <entry>@ 1 year 2 mons -3 days 4 hours 5 mins 6 secs ago</entry>
+         </row>
+        </tbody>
+       </tgroup>
+    </table>
+
+   </sect2>
+
    <sect2 id="datatype-datetime-internals">
     <title>Internals</title>
 
index d0a0284..6f977f9 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.267 2008/11/04 22:36:07 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/libpq.sgml,v 1.268 2008/11/09 00:28:34 tgl Exp $ -->
 
 <chapter id="libpq">
  <title><application>libpq</application> - C Library</title>
@@ -1019,13 +1019,15 @@ PQconninfoOption *PQconninfoParse(const char *conninfo, char **errmsg);
        <literal>is_superuser</>,
        <literal>session_authorization</>,
        <literal>DateStyle</>,
+       <literal>IntervalStyle</>,
        <literal>TimeZone</>,
        <literal>integer_datetimes</>, and
        <literal>standard_conforming_strings</>.
        (<literal>server_encoding</>, <literal>TimeZone</>, and
        <literal>integer_datetimes</> were not reported by releases before 8.0;
        <literal>standard_conforming_strings</> was not reported by releases
-       before 8.1.)
+       before 8.1; <literal>IntervalStyle</> was not reported by releases
+       before 8.4.)
        Note that
        <literal>server_version</>,
        <literal>server_encoding</> and
@@ -5765,6 +5767,17 @@ myEventProc(PGEventId evtId, void *evtInfo, void *passThrough)
     <listitem>
      <para>
       <indexterm>
+       <primary><envar>PGINTERVALSTYLE</envar></primary>
+      </indexterm>
+      <envar>PGINTERVALSTYLE</envar> sets the default style of interval
+      representation.  (Equivalent to <literal>SET intervalstyle TO
+      ...</literal>.)
+     </para>
+    </listitem>
+
+    <listitem>
+     <para>
+      <indexterm>
        <primary><envar>PGTZ</envar></primary>
       </indexterm>
       <envar>PGTZ</envar> sets the default time zone.  (Equivalent to
index c9a0c7a..3b115fe 100644 (file)
@@ -1,4 +1,4 @@
-<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.74 2008/10/28 12:10:42 mha Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/protocol.sgml,v 1.75 2008/11/09 00:28:34 tgl Exp $ -->
 
 <chapter id="protocol">
  <title>Frontend/Backend Protocol</title>
     <literal>is_superuser</>,
     <literal>session_authorization</>,
     <literal>DateStyle</>,
+    <literal>IntervalStyle</>,
     <literal>TimeZone</>,
     <literal>integer_datetimes</>, and
     <literal>standard_conforming_strings</>.
     (<literal>server_encoding</>, <literal>TimeZone</>, and
     <literal>integer_datetimes</> were not reported by releases before 8.0;
     <literal>standard_conforming_strings</> was not reported by releases
-    before 8.1.)
+    before 8.1; <literal>IntervalStyle</> was not reported by releases
+    before 8.4.)
     Note that
     <literal>server_version</>,
     <literal>server_encoding</> and
index 7624467..276e3d6 100644 (file)
@@ -1,5 +1,5 @@
 <!--
-$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.82 2008/10/10 21:46:34 tgl Exp $
+$PostgreSQL: pgsql/doc/src/sgml/ref/copy.sgml,v 1.83 2008/11/09 00:28:34 tgl Exp $
 PostgreSQL documentation
 -->
 
@@ -349,7 +349,11 @@ COPY <replaceable class="parameter">count</replaceable>
     <productname>PostgreSQL</productname> installations that might use
     non-default <varname>DateStyle</varname> settings,
     <varname>DateStyle</varname> should be set to <literal>ISO</> before
-    using <command>COPY TO</>.
+    using <command>COPY TO</>.  It is also a good idea to avoid dumping
+    data with <varname>IntervalStyle</varname> set to
+    <literal>sql_standard</>, because negative interval values might be
+    misinterpreted by a server that has a different setting for
+    <varname>IntervalStyle</varname>.
    </para>
 
    <para>
index 8efe2b2..e91c470 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.196 2008/11/08 20:51:49 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.197 2008/11/09 00:28:34 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -3101,6 +3101,11 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
                fmask |= tmask;
        }
 
+       /* ensure that at least one time field has been found */
+       if (fmask == 0)
+               return DTERR_BAD_FORMAT;
+
+       /* ensure fractional seconds are fractional */
        if (*fsec != 0)
        {
                int                     sec;
@@ -3114,6 +3119,60 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
                tm->tm_sec += sec;
        }
 
+       /*----------
+        * The SQL standard defines the interval literal
+        *   '-1 1:00:00'
+        * to mean "negative 1 days and negative 1 hours", while Postgres
+        * traditionally treats this as meaning "negative 1 days and positive
+        * 1 hours".  In SQL_STANDARD intervalstyle, we apply the leading sign
+        * to all fields if there are no other explicit signs.
+        *
+        * We leave the signs alone if there are additional explicit signs.
+        * This protects us against misinterpreting postgres-style dump output,
+        * since the postgres-style output code has always put an explicit sign on
+        * all fields following a negative field.  But note that SQL-spec output
+        * is ambiguous and can be misinterpreted on load!  (So it's best practice
+        * to dump in postgres style, not SQL style.)
+        *----------
+        */
+       if (IntervalStyle == INTSTYLE_SQL_STANDARD && *field[0] == '-')
+       {
+               /* Check for additional explicit signs */
+               bool    more_signs = false;
+
+               for (i = 1; i < nf; i++)
+               {
+                       if (*field[i] == '-' || *field[i] == '+')
+                       {
+                               more_signs = true;
+                               break;
+                       }
+               }
+
+               if (!more_signs)
+               {
+                       /*
+                        * Rather than re-determining which field was field[0], just
+                        * force 'em all negative.
+                        */
+                       if (*fsec > 0)
+                               *fsec = -(*fsec);
+                       if (tm->tm_sec > 0)
+                               tm->tm_sec = -tm->tm_sec;
+                       if (tm->tm_min > 0)
+                               tm->tm_min = -tm->tm_min;
+                       if (tm->tm_hour > 0)
+                               tm->tm_hour = -tm->tm_hour;
+                       if (tm->tm_mday > 0)
+                               tm->tm_mday = -tm->tm_mday;
+                       if (tm->tm_mon > 0)
+                               tm->tm_mon = -tm->tm_mon;
+                       if (tm->tm_year > 0)
+                               tm->tm_year = -tm->tm_year;
+               }
+       }
+
+       /* finally, AGO negates everything */
        if (is_before)
        {
                *fsec = -(*fsec);
@@ -3125,10 +3184,6 @@ DecodeInterval(char **field, int *ftype, int nf, int range,
                tm->tm_year = -tm->tm_year;
        }
 
-       /* ensure that at least one time field has been found */
-       if (fmask == 0)
-               return DTERR_BAD_FORMAT;
-
        return 0;
 }
 
@@ -3606,6 +3661,29 @@ EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style,
 }
 
 
+/*
+ * Helper function to avoid duplicated code in EncodeInterval below.
+ * Note that any sign is stripped from the input seconds values.
+ */
+static void
+AppendSeconds(char *cp, int sec, fsec_t fsec)
+{
+       if (fsec == 0)
+       {
+               sprintf(cp, ":%02d", abs(sec));
+       }
+       else
+       {
+#ifdef HAVE_INT64_TIMESTAMP
+               sprintf(cp, ":%02d.%06d", abs(sec), Abs(fsec));
+#else
+               sprintf(cp, ":%012.9f", fabs(sec + fsec));
+#endif
+               TrimTrailingZeros(cp);
+       }
+}
+
+
 /* EncodeInterval()
  * Interpret time structure as a delta time and convert to string.
  *
@@ -3613,23 +3691,115 @@ EncodeDateTime(struct pg_tm * tm, fsec_t fsec, int *tzp, char **tzn, int style,
  * Actually, afaik ISO does not address time interval formatting,
  *     but this looks similar to the spec for absolute date/time.
  * - thomas 1998-04-30
+ *
+ * Actually, afaik, ISO 8601 does specify formats for "time
+ * intervals...[of the]...format with time-unit designators", which
+ * are pretty ugly.  The format looks something like
+ *     P1Y1M1DT1H1M1.12345S
+ * but useful for exchanging data with computers instead of humans.
+ * - ron 2003-07-14
+ *
+ * And ISO's SQL 2008 standard specifies standards for
+ * "year-month literal"s (that look like '2-3') and
+ * "day-time literal"s (that look like ('4 5:6:7')
  */
 int
 EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
 {
+       char       *cp = str;
+       int                     year = tm->tm_year;
+       int                     mon  = tm->tm_mon;
+       int                     mday = tm->tm_mday;
+       int                     hour = tm->tm_hour;
+       int                     min  = tm->tm_min;
+       int                     sec  = tm->tm_sec;
        bool            is_before = FALSE;
        bool            is_nonzero = FALSE;
-       char       *cp = str;
 
        /*
         * The sign of year and month are guaranteed to match, since they are
         * stored internally as "month". But we'll need to check for is_before and
-        * is_nonzero when determining the signs of hour/minute/seconds fields.
+        * is_nonzero when determining the signs of day and hour/minute/seconds
+        * fields.
         */
        switch (style)
        {
-                       /* compatible with ISO date formats */
-               case USE_ISO_DATES:
+               /* SQL Standard interval format */
+               case INTSTYLE_SQL_STANDARD:
+                       {
+                               bool has_negative = year < 0 || mon  < 0 ||
+                                                                       mday < 0 || hour < 0 ||
+                                                                       min  < 0 || sec  < 0 || fsec < 0;
+                               bool has_positive = year > 0 || mon  > 0 ||
+                                                                       mday > 0 || hour > 0 ||
+                                                                       min  > 0 || sec  > 0 || fsec > 0;
+                               bool has_year_month = year != 0 || mon  != 0;
+                               bool has_day_time   = mday != 0 || hour != 0 ||
+                                                                         min  != 0 || sec  != 0 || fsec != 0;
+                               bool has_day        = mday != 0;
+                               bool sql_standard_value = !(has_negative && has_positive) &&
+                                                                                 !(has_year_month && has_day_time);
+
+                               /*
+                                * SQL Standard wants only 1 "<sign>" preceding the whole
+                                * interval ... but can't do that if mixed signs.
+                                */
+                               if (has_negative && sql_standard_value)
+                               {
+                                       *cp++ = '-';
+                                       year = -year;
+                                       mon  = -mon;
+                                       mday = -mday;
+                                       hour = -hour;
+                                       min  = -min;
+                                       sec  = -sec;
+                                       fsec = -fsec;
+                               }
+
+                               if (!has_negative && !has_positive)
+                               {
+                                       sprintf(cp, "0");
+                               }
+                               else if (!sql_standard_value)
+                               {
+                                       /*
+                                        * For non sql-standard interval values,
+                                        * force outputting the signs to avoid
+                                        * ambiguities with intervals with mixed
+                                        * sign components.
+                                        */
+                                       char year_sign = (year < 0 || mon < 0) ? '-' : '+';
+                                       char day_sign = (mday < 0) ? '-' : '+';
+                                       char sec_sign = (hour < 0 || min < 0 || sec < 0 || fsec < 0) ? '-' : '+';
+
+                                       sprintf(cp, "%c%d-%d %c%d %c%d:%02d",
+                                                       year_sign, abs(year), abs(mon),
+                                                       day_sign, abs(mday),
+                                                       sec_sign, abs(hour), abs(min));
+                                       cp += strlen(cp);
+                                       AppendSeconds(cp, sec, fsec);
+                               }
+                               else if (has_year_month)
+                               {
+                                       sprintf(cp, "%d-%d", year, mon);
+                               }
+                               else if (has_day)
+                               {
+                                       sprintf(cp, "%d %d:%02d", mday, hour, min);
+                                       cp += strlen(cp);
+                                       AppendSeconds(cp, sec, fsec);
+                               }
+                               else
+                               {
+                                       sprintf(cp, "%d:%02d", hour, min);
+                                       cp += strlen(cp);
+                                       AppendSeconds(cp, sec, fsec);
+                               }
+                       }
+                       break;
+
+               /* Compatible with postgresql < 8.4 when DateStyle = 'iso' */
+               case INTSTYLE_POSTGRES:
                        if (tm->tm_year != 0)
                        {
                                sprintf(cp, "%d year%s",
@@ -3669,32 +3839,20 @@ EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
                                                (minus ? "-" : (is_before ? "+" : "")),
                                                abs(tm->tm_hour), abs(tm->tm_min));
                                cp += strlen(cp);
-                               /* Mark as "non-zero" since the fields are now filled in */
+                               AppendSeconds(cp, tm->tm_sec, fsec);
+                               cp += strlen(cp);
                                is_nonzero = TRUE;
-
-                               /* need fractional seconds? */
-                               if (fsec != 0)
-                               {
-#ifdef HAVE_INT64_TIMESTAMP
-                                       sprintf(cp, ":%02d", abs(tm->tm_sec));
-                                       cp += strlen(cp);
-                                       sprintf(cp, ".%06d", Abs(fsec));
-#else
-                                       fsec += tm->tm_sec;
-                                       sprintf(cp, ":%012.9f", fabs(fsec));
-#endif
-                                       TrimTrailingZeros(cp);
-                                       cp += strlen(cp);
-                               }
-                               else
-                               {
-                                       sprintf(cp, ":%02d", abs(tm->tm_sec));
-                                       cp += strlen(cp);
-                               }
+                       }
+                       /* identically zero? then put in a unitless zero... */
+                       if (!is_nonzero)
+                       {
+                               strcat(cp, "0");
+                               cp += strlen(cp);
                        }
                        break;
 
-               case USE_POSTGRES_DATES:
+               /* Compatible with postgresql < 8.4 when DateStyle != 'iso' */
+               case INTSTYLE_POSTGRES_VERBOSE:
                default:
                        strcpy(cp, "@ ");
                        cp += strlen(cp);
@@ -3821,22 +3979,20 @@ EncodeInterval(struct pg_tm * tm, fsec_t fsec, int style, char *str)
                                        is_before = (tm->tm_sec < 0);
                                is_nonzero = TRUE;
                        }
+                       /* identically zero? then put in a unitless zero... */
+                       if (!is_nonzero)
+                       {
+                               strcat(cp, "0");
+                               cp += strlen(cp);
+                       }
+                       if (is_before)
+                       {
+                               strcat(cp, " ago");
+                               cp += strlen(cp);
+                       }
                        break;
        }
 
-       /* identically zero? then put in a unitless zero... */
-       if (!is_nonzero)
-       {
-               strcat(cp, "0");
-               cp += strlen(cp);
-       }
-
-       if (is_before && (style != USE_ISO_DATES))
-       {
-               strcat(cp, " ago");
-               cp += strlen(cp);
-       }
-
        return 0;
 }      /* EncodeInterval() */
 
index 4a505c3..6744818 100644 (file)
@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/nabstime.c,v 1.156 2008/09/10 18:29:41 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/nabstime.c,v 1.157 2008/11/09 00:28:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -671,7 +671,7 @@ reltimeout(PG_FUNCTION_ARGS)
        char            buf[MAXDATELEN + 1];
 
        reltime2tm(time, tm);
-       EncodeInterval(tm, 0, DateStyle, buf);
+       EncodeInterval(tm, 0, IntervalStyle, buf);
 
        result = pstrdup(buf);
        PG_RETURN_CSTRING(result);
index 7f80fc9..ce633c7 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.193 2008/10/14 15:44:29 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.194 2008/11/09 00:28:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -677,7 +677,7 @@ interval_out(PG_FUNCTION_ARGS)
        if (interval2tm(*span, tm, &fsec) != 0)
                elog(ERROR, "could not convert interval to tm");
 
-       if (EncodeInterval(tm, fsec, DateStyle, buf) != 0)
+       if (EncodeInterval(tm, fsec, IntervalStyle, buf) != 0)
                elog(ERROR, "could not format interval");
 
        result = pstrdup(buf);
index d0ce929..d187ce4 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.105 2008/02/17 02:09:29 tgl Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/init/globals.c,v 1.106 2008/11/09 00:28:35 tgl Exp $
  *
  * NOTES
  *       Globals used all over the place should be declared here and not
@@ -88,6 +88,7 @@ bool          ExitOnAnyError = false;
 
 int                    DateStyle = USE_ISO_DATES;
 int                    DateOrder = DATEORDER_MDY;
+int                    IntervalStyle = INTSTYLE_POSTGRES;
 bool           HasCTZSet = false;
 int                    CTimeZone = 0;
 
index 9fec575..6a5faa7 100644 (file)
@@ -10,7 +10,7 @@
  * Written by Peter Eisentraut <peter_e@gmx.net>.
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.475 2008/10/06 13:05:36 mha Exp $
+ *       $PostgreSQL: pgsql/src/backend/utils/misc/guc.c,v 1.476 2008/11/09 00:28:35 tgl Exp $
  *
  *--------------------------------------------------------------------
  */
@@ -213,6 +213,13 @@ static const struct config_enum_entry server_message_level_options[] = {
        {NULL, 0, false}
 };
 
+static const struct config_enum_entry intervalstyle_options[] = {
+       {"postgres", INTSTYLE_POSTGRES, false},
+       {"postgres_verbose", INTSTYLE_POSTGRES_VERBOSE, false},
+       {"sql_standard", INTSTYLE_SQL_STANDARD, false},
+       {NULL, 0, false}
+};
+
 static const struct config_enum_entry log_error_verbosity_options[] = {
        {"terse", PGERROR_TERSE, false},
        {"default", PGERROR_DEFAULT, false},
@@ -2519,6 +2526,16 @@ static struct config_enum ConfigureNamesEnum[] =
                XACT_READ_COMMITTED, isolation_level_options, NULL, NULL
        },
 
+       {
+               {"IntervalStyle", PGC_USERSET, CLIENT_CONN_LOCALE,
+                       gettext_noop("Sets the display format for interval values."),
+                       NULL,
+                       GUC_REPORT
+               },
+               &IntervalStyle,
+               INTSTYLE_POSTGRES, intervalstyle_options, NULL, NULL
+       },
+
        {
                {"log_error_verbosity", PGC_SUSET, LOGGING_WHEN,
                        gettext_noop("Sets the verbosity of logged messages."),
index 56afb2e..f886ef7 100644 (file)
 # - Locale and Formatting -
 
 #datestyle = 'iso, mdy'
+#intervalstyle = 'postgres'
 #timezone = unknown                    # actually, defaults to TZ environment
                                        # setting
 #timezone_abbreviations = 'Default'     # Select the set of available time zone
index ac05a4a..936ff42 100644 (file)
@@ -12,7 +12,7 @@
  *     by PostgreSQL
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.503 2008/10/31 08:39:21 heikki Exp $
+ *       $PostgreSQL: pgsql/src/bin/pg_dump/pg_dump.c,v 1.504 2008/11/09 00:28:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -568,6 +568,10 @@ main(int argc, char **argv)
        /* Set the datestyle to ISO to ensure the dump's portability */
        do_sql_command(g_conn, "SET DATESTYLE = ISO");
 
+       /* Likewise, avoid using sql_standard intervalstyle */
+       if (g_fout->remoteVersion >= 80400)
+               do_sql_command(g_conn, "SET INTERVALSTYLE = POSTGRES");
+
        /*
         * If supported, set extra_float_digits so that we can dump float data
         * exactly (given correctly implemented float I/O code, anyway)
index 24e50d0..8c38aaf 100644 (file)
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2000-2008, PostgreSQL Global Development Group
  *
- * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.174 2008/11/07 18:25:07 tgl Exp $
+ * $PostgreSQL: pgsql/src/bin/psql/tab-complete.c,v 1.175 2008/11/09 00:28:35 tgl Exp $
  */
 
 /*----------------------------------------------------------------------
@@ -1956,6 +1956,13 @@ psql_completion(char *text, int start, int end)
 
                        COMPLETE_WITH_LIST(my_list);
                }
+               else if (pg_strcasecmp(prev2_wd, "IntervalStyle") == 0)
+               {
+                       static const char *const my_list[] =
+                       {"postgres", "postgres_verbose", "sql_standard", NULL};
+
+                       COMPLETE_WITH_LIST(my_list);
+               }
                else if (pg_strcasecmp(prev2_wd, "GEQO") == 0)
                {
                        static const char *const my_list[] =
index 98e28e0..9348a52 100644 (file)
@@ -13,7 +13,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.203 2008/10/09 17:24:05 alvherre Exp $
+ * $PostgreSQL: pgsql/src/include/miscadmin.h,v 1.204 2008/11/09 00:28:35 tgl Exp $
  *
  * NOTES
  *       some of the information in this file should be moved to other files.
@@ -191,6 +191,18 @@ extern PGDLLIMPORT Oid MyDatabaseTableSpace;
 
 extern int     DateStyle;
 extern int     DateOrder;
+/*
+ * IntervalStyles
+ *   INTSTYLE_POSTGRES             Like Postgres < 8.4 when DateStyle = 'iso'
+ *   INTSTYLE_POSTGRES_VERBOSE     Like Postgres < 8.4 when DateStyle != 'iso'
+ *   INTSTYLE_SQL_STANDARD         SQL standard interval literals
+ */
+#define INTSTYLE_POSTGRES             0
+#define INTSTYLE_POSTGRES_VERBOSE     1
+#define INTSTYLE_SQL_STANDARD         2
+
+extern int     IntervalStyle;
 
 /*
  * HasCTZSet is true if user has set timezone as a numeric offset from UTC.
index 34c9cf1..d8b243b 100644 (file)
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.366 2008/11/03 14:18:57 mha Exp $
+ *       $PostgreSQL: pgsql/src/interfaces/libpq/fe-connect.c,v 1.367 2008/11/09 00:28:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -209,6 +209,9 @@ static const PQEnvironmentOption EnvironmentOptions[] =
                "PGDATESTYLE", "datestyle"
        },
        {
+               "PGINTERVALSTYLE", "intervalstyle"
+       },
+       {
                "PGTZ", "timezone"
        },
        {
index 8270516..e8fee7a 100644 (file)
@@ -2,6 +2,7 @@
 -- INTERVAL
 --
 SET DATESTYLE = 'ISO';
+SET IntervalStyle to postgres;
 -- check acceptance of "time zone style"
 SELECT INTERVAL '01:00' AS "One hour";
  One hour 
@@ -273,6 +274,7 @@ FROM INTERVAL_MULDIV_TBL;
 
 DROP TABLE INTERVAL_MULDIV_TBL;
 SET DATESTYLE = 'postgres';
+SET IntervalStyle to postgres_verbose;
 SELECT '' AS ten, * FROM INTERVAL_TBL;
  ten |              f1               
 -----+-------------------------------
@@ -326,6 +328,7 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
+SET IntervalStyle TO postgres;
 SELECT '1 millisecond'::interval, '1 microsecond'::interval,
        '500 seconds 99 milliseconds 51 microseconds'::interval;
    interval   |    interval     |    interval     
@@ -609,3 +612,37 @@ SELECT interval '1 2:03:04.5678' minute to second(2);
  00:03:04.57
 (1 row)
 
+-- test inputting and outputting SQL standard interval literals
+SET IntervalStyle TO sql_standard;
+SELECT  interval '0'                       AS "zero",
+        interval '1-2' year to month       AS "year-month",
+        interval '1 2:03:04' day to second AS "day-time",
+        - interval '1-2'                   AS "negative year-month",
+        - interval '1 2:03:04'             AS "negative day-time";
+ zero | year-month | day-time  | negative year-month | negative day-time 
+------+------------+-----------+---------------------+-------------------
+ 0    | 1-2        | 1 2:03:04 | -1-2                | -1 2:03:04
+(1 row)
+
+-- test input of some not-quite-standard interval values in the sql style
+SET IntervalStyle TO postgres;
+SELECT  interval '+1 -1:00:00',
+        interval '-1 +1:00:00',
+        interval '+1-2 -3 +4:05:06.789',
+        interval '-1-2 +3 -4:05:06.789';
+    interval     |     interval      |              interval               |                interval                
+-----------------+-------------------+-------------------------------------+----------------------------------------
+ 1 day -01:00:00 | -1 days +01:00:00 | 1 year 2 mons -3 days +04:05:06.789 | -1 years -2 mons +3 days -04:05:06.789
+(1 row)
+
+-- test output of couple non-standard interval values in the sql style
+SET IntervalStyle TO sql_standard;
+SELECT  interval '1 day -1 hours',
+        interval '-1 days +1 hours',
+        interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds',
+        - interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds';
+     interval     |     interval     |       interval       |       ?column?       
+------------------+------------------+----------------------+----------------------
+ +0-0 +1 -1:00:00 | +0-0 -1 +1:00:00 | +1-2 -3 +4:05:06.789 | -1-2 +3 -4:05:06.789
+(1 row)
+
index 93f99eb..8d4c3dd 100644 (file)
@@ -11,7 +11,7 @@
  * Portions Copyright (c) 1996-2008, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.48 2008/10/01 22:38:57 petere Exp $
+ * $PostgreSQL: pgsql/src/test/regress/pg_regress.c,v 1.49 2008/11/09 00:28:35 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -708,6 +708,7 @@ initialize_environment(void)
         */
        putenv("PGTZ=PST8PDT");
        putenv("PGDATESTYLE=Postgres, MDY");
+       putenv("PGINTERVALSTYLE=postgres_verbose");
 
        if (temp_install)
        {
index 732ca02..9b32dd6 100644 (file)
@@ -3,6 +3,7 @@
 --
 
 SET DATESTYLE = 'ISO';
+SET IntervalStyle to postgres;
 
 -- check acceptance of "time zone style"
 SELECT INTERVAL '01:00' AS "One hour";
@@ -94,6 +95,7 @@ FROM INTERVAL_MULDIV_TBL;
 DROP TABLE INTERVAL_MULDIV_TBL;
 
 SET DATESTYLE = 'postgres';
+SET IntervalStyle to postgres_verbose;
 
 SELECT '' AS ten, * FROM INTERVAL_TBL;
 
@@ -118,6 +120,8 @@ SELECT justify_interval(interval '1 month -1 hour') as "1 month -1 hour";
 
 -- test fractional second input, and detection of duplicate units
 SET DATESTYLE = 'ISO';
+SET IntervalStyle TO postgres;
+
 SELECT '1 millisecond'::interval, '1 microsecond'::interval,
        '500 seconds 99 milliseconds 51 microseconds'::interval;
 SELECT '3 days 5 milliseconds'::interval;
@@ -174,3 +178,25 @@ SELECT interval '1 2:03:04.5678' hour to second(2);
 SELECT interval '1 2.3456' minute to second(2);
 SELECT interval '1 2:03.5678' minute to second(2);
 SELECT interval '1 2:03:04.5678' minute to second(2);
+
+-- test inputting and outputting SQL standard interval literals
+SET IntervalStyle TO sql_standard;
+SELECT  interval '0'                       AS "zero",
+        interval '1-2' year to month       AS "year-month",
+        interval '1 2:03:04' day to second AS "day-time",
+        - interval '1-2'                   AS "negative year-month",
+        - interval '1 2:03:04'             AS "negative day-time";
+
+-- test input of some not-quite-standard interval values in the sql style
+SET IntervalStyle TO postgres;
+SELECT  interval '+1 -1:00:00',
+        interval '-1 +1:00:00',
+        interval '+1-2 -3 +4:05:06.789',
+        interval '-1-2 +3 -4:05:06.789';
+
+-- test output of couple non-standard interval values in the sql style
+SET IntervalStyle TO sql_standard;
+SELECT  interval '1 day -1 hours',
+        interval '-1 days +1 hours',
+        interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds',
+        - interval '1 years 2 months -3 days 4 hours 5 minutes 6.789 seconds';