提交 c880f9ae 编写于 作者: B Bruce Momjian

Update SQL-standard INTERVAL item:

        o Support ISO INTERVAL syntax if units cannot be determined from
          the string, and are supplied after the string

          The SQL standard states that the units after the string specify
          the units of the string, e.g. INTERVAL '2' MINUTE should
          return '00:02:00'.  The current behavior has the units
          restrict the interval value to the specified unit or unit range,
          INTERVAL '70' SECOND returns '00:00:10'.

          For syntax that isn't uniquely ISO or PG syntax, like '1' or
          '1:30', treat as ISO if there is a range specification clause,
          and as PG if there no clause is present, e.g. interpret
          '1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
          interpret '1:30' as '1 hour, 30 minutes'.

          This makes common cases like SELECT INTERVAL '1' MONTH
          SQL-standard results.  The SQL standard supports a limited
          number of unit combinations and doesn't support unit names
          in the string.  The PostgreSQL syntax is more flexible in
          the range of units supported, e.g. PostgreSQL supports
          '1 year 1 hour', while the SQL standard does not.
上级 02b59c6e
......@@ -2,7 +2,7 @@
PostgreSQL TODO List
====================
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
Last updated: Mon Apr 24 18:59:31 EDT 2006
Last updated: Mon Apr 24 20:00:38 EDT 2006
The most recent version of this document can be viewed at
http://www.postgresql.org/docs/faqs.TODO.html.
......@@ -241,13 +241,29 @@ Data Types
o Add ISO INTERVAL handling
o -Add support for day-time syntax, INTERVAL '1 2:03:04' DAY TO
SECOND
o Fix SELECT INTERVAL '1' MONTH
o Support ISO INTERVAL syntax if units cannot be determined from
the string, and are supplied after the string
The SQL standard states that the units after the string specify
the units of the string, e.g. INTERVAL '2' MINUTE should
return '00:02:00'. The current behavior has the units
restrict the interval value to the specified unit or unit range,
INTERVAL '70' SECOND returns '00:00:10'.
For syntax that isn't uniquely ISO or PG syntax, like '1' or
'1:30', treat as ISO if there is a range specification clause,
and as PG if there no clause is present, e.g. interpret
'1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
interpret '1:30' as '1 hour, 30 minutes'.
This makes common cases like SELECT INTERVAL '1' MONTH
SQL-standard results. The SQL standard supports a limited
number of unit combinations and doesn't support unit names
in the string. The PostgreSQL syntax is more flexible in
the range of units supported, e.g. PostgreSQL supports
'1 year 1 hour', while the SQL standard does not.
o Add support for year-month syntax, INTERVAL '50-6' YEAR TO MONTH
o For syntax that isn't uniquely ISO or PG syntax, like '1:30' or
'1', treat as ISO if there is a range specification clause,
and as PG if there no clause is present, e.g. interpret
'1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
interpret '1:30' as '1 hour, 30 minutes'
o Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
INTERVAL MONTH), and this should return '12 months'
o Round or truncate values to the requested precision, e.g.
......
......@@ -8,7 +8,7 @@
<body bgcolor="#FFFFFF" text="#000000" link="#FF0000" vlink="#A00000" alink="#0000FF">
<h1><a name="section_1">PostgreSQL TODO List</a></h1>
<p>Current maintainer: Bruce Momjian (<a href="mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</a>)<br/>
Last updated: Mon Apr 24 18:59:31 EDT 2006
Last updated: Mon Apr 24 20:00:38 EDT 2006
</p>
<p>The most recent version of this document can be viewed at<br/>
<a href="http://www.postgresql.org/docs/faqs.TODO.html">http://www.postgresql.org/docs/faqs.TODO.html</a>.
......@@ -223,20 +223,35 @@ first.
<ul>
<li>-<em>Add support for day-time syntax, INTERVAL '1 2:03:04' DAY TO </em>
SECOND
</li><li>Fix SELECT INTERVAL '1' MONTH
</li><li>Support ISO INTERVAL syntax if units cannot be determined from
the string, and are supplied after the string
<p> The SQL standard states that the units after the string specify
the units of the string, e.g. INTERVAL '2' MINUTE should
return '00:02:00'. The current behavior has the units
restrict the interval value to the specified unit or unit range,
INTERVAL '70' SECOND returns '00:00:10'.
</p>
<p> For syntax that isn't uniquely ISO or PG syntax, like '1' or
'1:30', treat as ISO if there is a range specification clause,
and as PG if there no clause is present, e.g. interpret
'1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
interpret '1:30' as '1 hour, 30 minutes'.
</p>
<p> This makes common cases like SELECT INTERVAL '1' MONTH
SQL-standard results. The SQL standard supports a limited
number of unit combinations and doesn't support unit names
in the string. The PostgreSQL syntax is more flexible in
the range of units supported, e.g. PostgreSQL supports
'1 year 1 hour', while the SQL standard does not.
</p>
</li><li>Add support for year-month syntax, INTERVAL '50-6' YEAR TO MONTH
</li><li>For syntax that isn't uniquely ISO or PG syntax, like '1:30' or
'1', treat as ISO if there is a range specification clause,
and as PG if there no clause is present, e.g. interpret
<p> '1:30' MINUTE TO SECOND as '1 minute 30 seconds', and
interpret '1:30' as '1 hour, 30 minutes'
<li>Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
</li><li>Interpret INTERVAL '1 year' MONTH as CAST (INTERVAL '1 year' AS
INTERVAL MONTH), and this should return '12 months'
</li><li>Round or truncate values to the requested precision, e.g.
INTERVAL '11 months' AS YEAR should return one or zero
</li><li>Support precision, CREATE TABLE foo (a INTERVAL MONTH(3))
</li></ul>
</p></ul>
</li></ul>
</li><li>Arrays
<ul>
<li>-<em>Allow NULLs in arrays</em>
......@@ -1176,6 +1191,6 @@ first.
</li><li>Teodor is Teodor Sigaev &lt;<a href="mailto:teodor@sigaev.ru">teodor@sigaev.ru</a>&gt;
</li><li>Tom is Tom Lane &lt;<a href="mailto:tgl@sss.pgh.pa.us">tgl@sss.pgh.pa.us</a>&gt; of Red Hat
</li></ul>
</li></ul></li></ul>
</body>
</html>
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