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><DIV
CLASS="SECT1"
><H1
CLASS="SECT1"
><A
NAME="FUNCTIONS-FORMATTING"
>9.8. Data Type Formatting Functions</A
></H1
><P
> The <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
> formatting functions
provide a powerful set of tools for converting various data types
(date/time, integer, floating point, numeric) to formatted strings
and for converting from formatted strings to specific data types.
<A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-TABLE"
>Table 9-21</A
> lists them.
These functions all follow a common calling convention: the first
argument is the value to be formatted and the second argument is a
template that defines the output or input format.
</P
><P
> A single-argument <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
> function is also
available; it accepts a
<TT
CLASS="TYPE"
>double precision</TT
> argument and converts from Unix epoch
(seconds since 1970-01-01 00:00:00+00) to
<TT
CLASS="TYPE"
>timestamp with time zone</TT
>.
(<TT
CLASS="TYPE"
>Integer</TT
> Unix epochs are implicitly cast to
<TT
CLASS="TYPE"
>double precision</TT
>.)
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-TABLE"
></A
><P
><B
>Table 9-21. Formatting Functions</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><COL><THEAD
><TR
><TH
>Function</TH
><TH
>Return Type</TH
><TH
>Description</TH
><TH
>Example</TH
></TR
></THEAD
><TBODY
><TR
><TD
>
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_char(<TT
CLASS="TYPE"
>timestamp</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
>
</TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>convert time stamp to string</TD
><TD
><TT
CLASS="LITERAL"
>to_char(current_timestamp, 'HH12:MI:SS')</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_char(<TT
CLASS="TYPE"
>interval</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>convert interval to string</TD
><TD
><TT
CLASS="LITERAL"
>to_char(interval '15h 2m 12s', 'HH24:MI:SS')</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_char(<TT
CLASS="TYPE"
>int</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>convert integer to string</TD
><TD
><TT
CLASS="LITERAL"
>to_char(125, '999')</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_char</CODE
>(<TT
CLASS="TYPE"
>double precision</TT
>,
<TT
CLASS="TYPE"
>text</TT
>)</TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>convert real/double precision to string</TD
><TD
><TT
CLASS="LITERAL"
>to_char(125.8::real, '999D9')</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_char(<TT
CLASS="TYPE"
>numeric</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
></TD
><TD
><TT
CLASS="TYPE"
>text</TT
></TD
><TD
>convert numeric to string</TD
><TD
><TT
CLASS="LITERAL"
>to_char(-125.8, '999D99S')</TT
></TD
></TR
><TR
><TD
>
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_date(<TT
CLASS="TYPE"
>text</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
>
</TD
><TD
><TT
CLASS="TYPE"
>date</TT
></TD
><TD
>convert string to date</TD
><TD
><TT
CLASS="LITERAL"
>to_date('05 Dec 2000', 'DD Mon YYYY')</TT
></TD
></TR
><TR
><TD
>
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_number(<TT
CLASS="TYPE"
>text</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
>
</TD
><TD
><TT
CLASS="TYPE"
>numeric</TT
></TD
><TD
>convert string to numeric</TD
><TD
><TT
CLASS="LITERAL"
>to_number('12,454.8-', '99G999D9S')</TT
></TD
></TR
><TR
><TD
>
<TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_timestamp(<TT
CLASS="TYPE"
>text</TT
>, <TT
CLASS="TYPE"
>text</TT
>)</CODE
></TT
>
</TD
><TD
><TT
CLASS="TYPE"
>timestamp with time zone</TT
></TD
><TD
>convert string to time stamp</TD
><TD
><TT
CLASS="LITERAL"
>to_timestamp('05 Dec 2000', 'DD Mon YYYY')</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
><CODE
CLASS="FUNCTION"
>to_timestamp(<TT
CLASS="TYPE"
>double precision</TT
>)</CODE
></TT
></TD
><TD
><TT
CLASS="TYPE"
>timestamp with time zone</TT
></TD
><TD
>convert Unix epoch to time stamp</TD
><TD
><TT
CLASS="LITERAL"
>to_timestamp(1284352323)</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><P
> In a <CODE
CLASS="FUNCTION"
>to_char</CODE
> output template string, there are certain
patterns that are recognized and replaced with appropriately-formatted
data based on the given value. Any text that is not a template pattern is
simply copied verbatim. Similarly, in an input template string (for the
other functions), template patterns identify the values to be supplied by
the input data string.
</P
><P
> <A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-DATETIME-TABLE"
>Table 9-22</A
> shows the
template patterns available for formatting date and time values.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-DATETIME-TABLE"
></A
><P
><B
>Table 9-22. Template Patterns for Date/Time Formatting</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Pattern</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>HH</TT
></TD
><TD
>hour of day (01-12)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>HH12</TT
></TD
><TD
>hour of day (01-12)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>HH24</TT
></TD
><TD
>hour of day (00-23)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MI</TT
></TD
><TD
>minute (00-59)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SS</TT
></TD
><TD
>second (00-59)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MS</TT
></TD
><TD
>millisecond (000-999)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>US</TT
></TD
><TD
>microsecond (000000-999999)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SSSS</TT
></TD
><TD
>seconds past midnight (0-86399)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>AM</TT
>, <TT
CLASS="LITERAL"
>am</TT
>,
<TT
CLASS="LITERAL"
>PM</TT
> or <TT
CLASS="LITERAL"
>pm</TT
></TD
><TD
>meridiem indicator (without periods)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>A.M.</TT
>, <TT
CLASS="LITERAL"
>a.m.</TT
>,
<TT
CLASS="LITERAL"
>P.M.</TT
> or <TT
CLASS="LITERAL"
>p.m.</TT
></TD
><TD
>meridiem indicator (with periods)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Y,YYY</TT
></TD
><TD
>year (4 or more digits) with comma</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>YYYY</TT
></TD
><TD
>year (4 or more digits)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>YYY</TT
></TD
><TD
>last 3 digits of year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>YY</TT
></TD
><TD
>last 2 digits of year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Y</TT
></TD
><TD
>last digit of year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>IYYY</TT
></TD
><TD
>ISO 8601 week-numbering year (4 or more digits)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>IYY</TT
></TD
><TD
>last 3 digits of ISO 8601 week-numbering year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>IY</TT
></TD
><TD
>last 2 digits of ISO 8601 week-numbering year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>I</TT
></TD
><TD
>last digit of ISO 8601 week-numbering year</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>BC</TT
>, <TT
CLASS="LITERAL"
>bc</TT
>,
<TT
CLASS="LITERAL"
>AD</TT
> or <TT
CLASS="LITERAL"
>ad</TT
></TD
><TD
>era indicator (without periods)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>B.C.</TT
>, <TT
CLASS="LITERAL"
>b.c.</TT
>,
<TT
CLASS="LITERAL"
>A.D.</TT
> or <TT
CLASS="LITERAL"
>a.d.</TT
></TD
><TD
>era indicator (with periods)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MONTH</TT
></TD
><TD
>full upper case month name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Month</TT
></TD
><TD
>full capitalized month name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>month</TT
></TD
><TD
>full lower case month name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MON</TT
></TD
><TD
>abbreviated upper case month name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Mon</TT
></TD
><TD
>abbreviated capitalized month name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>mon</TT
></TD
><TD
>abbreviated lower case month name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MM</TT
></TD
><TD
>month number (01-12)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>DAY</TT
></TD
><TD
>full upper case day name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Day</TT
></TD
><TD
>full capitalized day name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>day</TT
></TD
><TD
>full lower case day name (blank-padded to 9 chars)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>DY</TT
></TD
><TD
>abbreviated upper case day name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Dy</TT
></TD
><TD
>abbreviated capitalized day name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>dy</TT
></TD
><TD
>abbreviated lower case day name (3 chars in English, localized lengths vary)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>DDD</TT
></TD
><TD
>day of year (001-366)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>IDDD</TT
></TD
><TD
>day of ISO 8601 week-numbering year (001-371; day 1 of the year is Monday of the first ISO week)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>DD</TT
></TD
><TD
>day of month (01-31)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>D</TT
></TD
><TD
>day of the week, Sunday (<TT
CLASS="LITERAL"
>1</TT
>) to Saturday (<TT
CLASS="LITERAL"
>7</TT
>)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>ID</TT
></TD
><TD
>ISO 8601 day of the week, Monday (<TT
CLASS="LITERAL"
>1</TT
>) to Sunday (<TT
CLASS="LITERAL"
>7</TT
>)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>W</TT
></TD
><TD
>week of month (1-5) (the first week starts on the first day of the month)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>WW</TT
></TD
><TD
>week number of year (1-53) (the first week starts on the first day of the year)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>IW</TT
></TD
><TD
>week number of ISO 8601 week-numbering year (01-53; the first Thursday of the year is in week 1)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>CC</TT
></TD
><TD
>century (2 digits) (the twenty-first century starts on 2001-01-01)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>J</TT
></TD
><TD
>Julian Day (days since November 24, 4714 BC at midnight)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>Q</TT
></TD
><TD
>quarter (ignored by <CODE
CLASS="FUNCTION"
>to_date</CODE
> and <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
>)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>RM</TT
></TD
><TD
>month in upper case Roman numerals (I-XII; I=January)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>rm</TT
></TD
><TD
>month in lower case Roman numerals (i-xii; i=January)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>TZ</TT
></TD
><TD
>upper case time-zone abbreviation
(only supported in <CODE
CLASS="FUNCTION"
>to_char</CODE
>)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>tz</TT
></TD
><TD
>lower case time-zone abbreviation
(only supported in <CODE
CLASS="FUNCTION"
>to_char</CODE
>)</TD
></TR
></TBODY
></TABLE
></DIV
><P
> Modifiers can be applied to any template pattern to alter its
behavior. For example, <TT
CLASS="LITERAL"
>FMMonth</TT
>
is the <TT
CLASS="LITERAL"
>Month</TT
> pattern with the
<TT
CLASS="LITERAL"
>FM</TT
> modifier.
<A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-DATETIMEMOD-TABLE"
>Table 9-23</A
> shows the
modifier patterns for date/time formatting.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-DATETIMEMOD-TABLE"
></A
><P
><B
>Table 9-23. Template Pattern Modifiers for Date/Time Formatting</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
>Modifier</TH
><TH
>Description</TH
><TH
>Example</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>FM</TT
> prefix</TD
><TD
>fill mode (suppress leading zeroes and padding blanks)</TD
><TD
><TT
CLASS="LITERAL"
>FMMonth</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>TH</TT
> suffix</TD
><TD
>upper case ordinal number suffix</TD
><TD
><TT
CLASS="LITERAL"
>DDTH</TT
>, e.g., <TT
CLASS="LITERAL"
>12TH</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>th</TT
> suffix</TD
><TD
>lower case ordinal number suffix</TD
><TD
><TT
CLASS="LITERAL"
>DDth</TT
>, e.g., <TT
CLASS="LITERAL"
>12th</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>FX</TT
> prefix</TD
><TD
>fixed format global option (see usage notes)</TD
><TD
><TT
CLASS="LITERAL"
>FX Month DD Day</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>TM</TT
> prefix</TD
><TD
>translation mode (print localized day and month names based on
<A
HREF="runtime-config-client.html#GUC-LC-TIME"
>lc_time</A
>)</TD
><TD
><TT
CLASS="LITERAL"
>TMMonth</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SP</TT
> suffix</TD
><TD
>spell mode (not implemented)</TD
><TD
><TT
CLASS="LITERAL"
>DDSP</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><P
> Usage notes for date/time formatting:
<P
></P
></P><UL
><LI
><P
> <TT
CLASS="LITERAL"
>FM</TT
> suppresses leading zeroes and trailing blanks
that would otherwise be added to make the output of a pattern be
fixed-width. In <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>,
<TT
CLASS="LITERAL"
>FM</TT
> modifies only the next specification, while in
Oracle <TT
CLASS="LITERAL"
>FM</TT
> affects all subsequent
specifications, and repeated <TT
CLASS="LITERAL"
>FM</TT
> modifiers
toggle fill mode on and off.
</P
></LI
><LI
><P
> <TT
CLASS="LITERAL"
>TM</TT
> does not include trailing blanks.
</P
></LI
><LI
><P
> <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
> and <CODE
CLASS="FUNCTION"
>to_date</CODE
>
skip multiple blank spaces in the input string unless the
<TT
CLASS="LITERAL"
>FX</TT
> option is used. For example,
<TT
CLASS="LITERAL"
>to_timestamp('2000 JUN', 'YYYY MON')</TT
> works, but
<TT
CLASS="LITERAL"
>to_timestamp('2000 JUN', 'FXYYYY MON')</TT
> returns an error
because <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
> expects one space only.
<TT
CLASS="LITERAL"
>FX</TT
> must be specified as the first item in
the template.
</P
></LI
><LI
><P
> Ordinary text is allowed in <CODE
CLASS="FUNCTION"
>to_char</CODE
>
templates and will be output literally. You can put a substring
in double quotes to force it to be interpreted as literal text
even if it contains pattern key words. For example, in
<TT
CLASS="LITERAL"
>'"Hello Year "YYYY'</TT
>, the <TT
CLASS="LITERAL"
>YYYY</TT
>
will be replaced by the year data, but the single <TT
CLASS="LITERAL"
>Y</TT
> in <TT
CLASS="LITERAL"
>Year</TT
>
will not be. In <CODE
CLASS="FUNCTION"
>to_date</CODE
>, <CODE
CLASS="FUNCTION"
>to_number</CODE
>,
and <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
>, double-quoted strings skip the number of
input characters contained in the string, e.g. <TT
CLASS="LITERAL"
>"XX"</TT
>
skips two input characters.
</P
></LI
><LI
><P
> If you want to have a double quote in the output you must
precede it with a backslash, for example <TT
CLASS="LITERAL"
>'\"YYYY
Month\"'</TT
>.
</P
></LI
><LI
><P
> If the year format specification is less than four digits, e.g.
<TT
CLASS="LITERAL"
>YYY</TT
>, and the supplied year is less than four digits,
the year will be adjusted to be nearest to the year 2020, e.g.
<TT
CLASS="LITERAL"
>95</TT
> becomes 1995.
</P
></LI
><LI
><P
> The <TT
CLASS="LITERAL"
>YYYY</TT
> conversion from string to <TT
CLASS="TYPE"
>timestamp</TT
> or
<TT
CLASS="TYPE"
>date</TT
> has a restriction when processing years with more than 4 digits. You must
use some non-digit character or template after <TT
CLASS="LITERAL"
>YYYY</TT
>,
otherwise the year is always interpreted as 4 digits. For example
(with the year 20000):
<TT
CLASS="LITERAL"
>to_date('200001131', 'YYYYMMDD')</TT
> will be
interpreted as a 4-digit year; instead use a non-digit
separator after the year, like
<TT
CLASS="LITERAL"
>to_date('20000-1131', 'YYYY-MMDD')</TT
> or
<TT
CLASS="LITERAL"
>to_date('20000Nov31', 'YYYYMonDD')</TT
>.
</P
></LI
><LI
><P
> In conversions from string to <TT
CLASS="TYPE"
>timestamp</TT
> or
<TT
CLASS="TYPE"
>date</TT
>, the <TT
CLASS="LITERAL"
>CC</TT
> (century) field is ignored
if there is a <TT
CLASS="LITERAL"
>YYY</TT
>, <TT
CLASS="LITERAL"
>YYYY</TT
> or
<TT
CLASS="LITERAL"
>Y,YYY</TT
> field. If <TT
CLASS="LITERAL"
>CC</TT
> is used with
<TT
CLASS="LITERAL"
>YY</TT
> or <TT
CLASS="LITERAL"
>Y</TT
> then the year is computed
as <TT
CLASS="LITERAL"
>(CC-1)*100+YY</TT
>.
</P
></LI
><LI
><P
> An ISO 8601 week-numbering date (as distinct from a Gregorian date)
can be specified to <CODE
CLASS="FUNCTION"
>to_timestamp</CODE
> and
<CODE
CLASS="FUNCTION"
>to_date</CODE
> in one of two ways:
<P
></P
></P><UL
><LI
><P
> Year, week number, and weekday: for
example <TT
CLASS="LITERAL"
>to_date('2006-42-4', 'IYYY-IW-ID')</TT
>
returns the date <TT
CLASS="LITERAL"
>2006-10-19</TT
>.
If you omit the weekday it is assumed to be 1 (Monday).
</P
></LI
><LI
><P
> Year and day of year: for example <TT
CLASS="LITERAL"
>to_date('2006-291',
'IYYY-IDDD')</TT
> also returns <TT
CLASS="LITERAL"
>2006-10-19</TT
>.
</P
></LI
></UL
><P>
</P
><P
> Attempting to enter a date using a mixture of ISO 8601 week-numbering
fields and Gregorian date fields is nonsensical, and will cause an
error. In the context of an ISO 8601 week-numbering year, the
concept of a <SPAN
CLASS="QUOTE"
>"month"</SPAN
> or <SPAN
CLASS="QUOTE"
>"day of month"</SPAN
> has no
meaning. In the context of a Gregorian year, the ISO week has no
meaning.
</P
><DIV
CLASS="CAUTION"
><P
></P
><TABLE
CLASS="CAUTION"
BORDER="1"
WIDTH="90%"
><TR
><TD
ALIGN="CENTER"
><B
>Caution</B
></TD
></TR
><TR
><TD
ALIGN="LEFT"
><P
> While <CODE
CLASS="FUNCTION"
>to_date</CODE
> will reject a mixture of
Gregorian and ISO week-numbering date
fields, <CODE
CLASS="FUNCTION"
>to_char</CODE
> will not, since output format
specifications like <TT
CLASS="LITERAL"
>YYYY-MM-DD (IYYY-IDDD)</TT
> can be
useful. But avoid writing something like <TT
CLASS="LITERAL"
>IYYY-MM-DD</TT
>;
that would yield surprising results near the start of the year.
(See <A
HREF="functions-datetime.html#FUNCTIONS-DATETIME-EXTRACT"
>Section 9.9.1</A
> for more
information.)
</P
></TD
></TR
></TABLE
></DIV
></LI
><LI
><P
> In a conversion from string to <TT
CLASS="TYPE"
>timestamp</TT
>, millisecond
(<TT
CLASS="LITERAL"
>MS</TT
>) or microsecond (<TT
CLASS="LITERAL"
>US</TT
>)
values are used as the
seconds digits after the decimal point. For example
<TT
CLASS="LITERAL"
>to_timestamp('12:3', 'SS:MS')</TT
> is not 3 milliseconds,
but 300, because the conversion counts it as 12 + 0.3 seconds.
This means for the format <TT
CLASS="LITERAL"
>SS:MS</TT
>, the input values
<TT
CLASS="LITERAL"
>12:3</TT
>, <TT
CLASS="LITERAL"
>12:30</TT
>, and <TT
CLASS="LITERAL"
>12:300</TT
> specify the
same number of milliseconds. To get three milliseconds, one must use
<TT
CLASS="LITERAL"
>12:003</TT
>, which the conversion counts as
12 + 0.003 = 12.003 seconds.
</P
><P
> Here is a more
complex example:
<TT
CLASS="LITERAL"
>to_timestamp('15:12:02.020.001230', 'HH24:MI:SS.MS.US')</TT
>
is 15 hours, 12 minutes, and 2 seconds + 20 milliseconds +
1230 microseconds = 2.021230 seconds.
</P
></LI
><LI
><P
> <CODE
CLASS="FUNCTION"
>to_char(..., 'ID')</CODE
>'s day of the week numbering
matches the <CODE
CLASS="FUNCTION"
>extract(isodow from ...)</CODE
> function, but
<CODE
CLASS="FUNCTION"
>to_char(..., 'D')</CODE
>'s does not match
<CODE
CLASS="FUNCTION"
>extract(dow from ...)</CODE
>'s day numbering.
</P
></LI
><LI
><P
> <CODE
CLASS="FUNCTION"
>to_char(interval)</CODE
> formats <TT
CLASS="LITERAL"
>HH</TT
> and
<TT
CLASS="LITERAL"
>HH12</TT
> as shown on a 12-hour clock, i.e. zero hours
and 36 hours output as <TT
CLASS="LITERAL"
>12</TT
>, while <TT
CLASS="LITERAL"
>HH24</TT
>
outputs the full hour value, which can exceed 23 for intervals.
</P
></LI
></UL
><P>
</P
><P
> <A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-NUMERIC-TABLE"
>Table 9-24</A
> shows the
template patterns available for formatting numeric values.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-NUMERIC-TABLE"
></A
><P
><B
>Table 9-24. Template Patterns for Numeric Formatting</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Pattern</TH
><TH
>Description</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>9</TT
></TD
><TD
>digit position (can be dropped if insignificant)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>0</TT
></TD
><TD
>digit position (will not be dropped, even if insignificant)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>.</TT
> (period)</TD
><TD
>decimal point</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>,</TT
> (comma)</TD
><TD
>group (thousands) separator</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>PR</TT
></TD
><TD
>negative value in angle brackets</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>S</TT
></TD
><TD
>sign anchored to number (uses locale)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>L</TT
></TD
><TD
>currency symbol (uses locale)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>D</TT
></TD
><TD
>decimal point (uses locale)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>G</TT
></TD
><TD
>group separator (uses locale)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>MI</TT
></TD
><TD
>minus sign in specified position (if number < 0)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>PL</TT
></TD
><TD
>plus sign in specified position (if number > 0)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>SG</TT
></TD
><TD
>plus/minus sign in specified position</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>RN</TT
></TD
><TD
>Roman numeral (input between 1 and 3999)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>TH</TT
> or <TT
CLASS="LITERAL"
>th</TT
></TD
><TD
>ordinal number suffix</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>V</TT
></TD
><TD
>shift specified number of digits (see notes)</TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>EEEE</TT
></TD
><TD
>exponent for scientific notation</TD
></TR
></TBODY
></TABLE
></DIV
><P
> Usage notes for numeric formatting:
<P
></P
></P><UL
><LI
><P
> <TT
CLASS="LITERAL"
>0</TT
> specifies a digit position that will always be printed,
even if it contains a leading/trailing zero. <TT
CLASS="LITERAL"
>9</TT
> also
specifies a digit position, but if it is a leading zero then it will
be replaced by a space, while if it is a trailing zero and fill mode
is specified then it will be deleted. (For <CODE
CLASS="FUNCTION"
>to_number()</CODE
>,
these two pattern characters are equivalent.)
</P
></LI
><LI
><P
> The pattern characters <TT
CLASS="LITERAL"
>S</TT
>, <TT
CLASS="LITERAL"
>L</TT
>, <TT
CLASS="LITERAL"
>D</TT
>,
and <TT
CLASS="LITERAL"
>G</TT
> represent the sign, currency symbol, decimal point,
and thousands separator characters defined by the current locale
(see <A
HREF="runtime-config-client.html#GUC-LC-MONETARY"
>lc_monetary</A
>
and <A
HREF="runtime-config-client.html#GUC-LC-NUMERIC"
>lc_numeric</A
>). The pattern characters period
and comma represent those exact characters, with the meanings of
decimal point and thousands separator, regardless of locale.
</P
></LI
><LI
><P
> If no explicit provision is made for a sign
in <CODE
CLASS="FUNCTION"
>to_char()</CODE
>'s pattern, one column will be reserved for
the sign, and it will be anchored to (appear just left of) the
number. If <TT
CLASS="LITERAL"
>S</TT
> appears just left of some <TT
CLASS="LITERAL"
>9</TT
>'s,
it will likewise be anchored to the number.
</P
></LI
><LI
><P
> A sign formatted using <TT
CLASS="LITERAL"
>SG</TT
>, <TT
CLASS="LITERAL"
>PL</TT
>, or
<TT
CLASS="LITERAL"
>MI</TT
> is not anchored to
the number; for example,
<TT
CLASS="LITERAL"
>to_char(-12, 'MI9999')</TT
> produces <TT
CLASS="LITERAL"
>'- 12'</TT
>
but <TT
CLASS="LITERAL"
>to_char(-12, 'S9999')</TT
> produces <TT
CLASS="LITERAL"
>' -12'</TT
>.
(The Oracle implementation does not allow the use of
<TT
CLASS="LITERAL"
>MI</TT
> before <TT
CLASS="LITERAL"
>9</TT
>, but rather
requires that <TT
CLASS="LITERAL"
>9</TT
> precede
<TT
CLASS="LITERAL"
>MI</TT
>.)
</P
></LI
><LI
><P
> <TT
CLASS="LITERAL"
>TH</TT
> does not convert values less than zero
and does not convert fractional numbers.
</P
></LI
><LI
><P
> <TT
CLASS="LITERAL"
>PL</TT
>, <TT
CLASS="LITERAL"
>SG</TT
>, and
<TT
CLASS="LITERAL"
>TH</TT
> are <SPAN
CLASS="PRODUCTNAME"
>PostgreSQL</SPAN
>
extensions.
</P
></LI
><LI
><P
> <TT
CLASS="LITERAL"
>V</TT
> effectively
multiplies the input values by
<TT
CLASS="LITERAL"
>10^<TT
CLASS="REPLACEABLE"
><I
>n</I
></TT
></TT
>, where
<TT
CLASS="REPLACEABLE"
><I
>n</I
></TT
> is the number of digits following
<TT
CLASS="LITERAL"
>V</TT
>.
<CODE
CLASS="FUNCTION"
>to_char</CODE
> does not support the use of
<TT
CLASS="LITERAL"
>V</TT
> combined with a decimal point
(e.g., <TT
CLASS="LITERAL"
>99.9V99</TT
> is not allowed).
</P
></LI
><LI
><P
> <TT
CLASS="LITERAL"
>EEEE</TT
> (scientific notation) cannot be used in
combination with any of the other formatting patterns or
modifiers other than digit and decimal point patterns, and must be at the end of the format string
(e.g., <TT
CLASS="LITERAL"
>9.99EEEE</TT
> is a valid pattern).
</P
></LI
></UL
><P>
</P
><P
> Certain modifiers can be applied to any template pattern to alter its
behavior. For example, <TT
CLASS="LITERAL"
>FM99.99</TT
>
is the <TT
CLASS="LITERAL"
>99.99</TT
> pattern with the
<TT
CLASS="LITERAL"
>FM</TT
> modifier.
<A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-NUMERICMOD-TABLE"
>Table 9-25</A
> shows the
modifier patterns for numeric formatting.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-NUMERICMOD-TABLE"
></A
><P
><B
>Table 9-25. Template Pattern Modifiers for Numeric Formatting</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><COL><THEAD
><TR
><TH
>Modifier</TH
><TH
>Description</TH
><TH
>Example</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>FM</TT
> prefix</TD
><TD
>fill mode (suppress trailing zeroes and padding blanks)</TD
><TD
><TT
CLASS="LITERAL"
>FM99.99</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>TH</TT
> suffix</TD
><TD
>upper case ordinal number suffix</TD
><TD
><TT
CLASS="LITERAL"
>999TH</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>th</TT
> suffix</TD
><TD
>lower case ordinal number suffix</TD
><TD
><TT
CLASS="LITERAL"
>999th</TT
></TD
></TR
></TBODY
></TABLE
></DIV
><P
> <A
HREF="functions-formatting.html#FUNCTIONS-FORMATTING-EXAMPLES-TABLE"
>Table 9-26</A
> shows some
examples of the use of the <CODE
CLASS="FUNCTION"
>to_char</CODE
> function.
</P
><DIV
CLASS="TABLE"
><A
NAME="FUNCTIONS-FORMATTING-EXAMPLES-TABLE"
></A
><P
><B
>Table 9-26. <CODE
CLASS="FUNCTION"
>to_char</CODE
> Examples</B
></P
><TABLE
BORDER="1"
CLASS="CALSTABLE"
><COL><COL><THEAD
><TR
><TH
>Expression</TH
><TH
>Result</TH
></TR
></THEAD
><TBODY
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(current_timestamp, 'Day, DD HH12:MI:SS')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'Tuesday , 06 05:39:18'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(current_timestamp, 'FMDay, FMDD HH12:MI:SS')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'Tuesday, 6 05:39:18'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-0.1, '99.99')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' -.10'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-0.1, 'FM9.99')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'-.1'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-0.1, 'FM90.99')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'-0.1'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(0.1, '0.9')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 0.1'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(12, '9990999.9')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 0012.0'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(12, 'FM9990999.9')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'0012.'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, '999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, '999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'-485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, '9 9 9')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 4 8 5'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(1485, '9,999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 1,485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(1485, '9G999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 1 485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(148.5, '999.999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 148.500'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(148.5, 'FM999.999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'148.5'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(148.5, 'FM999.990')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'148.500'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(148.5, '999D999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 148,500'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(3148.5, '9G999D999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 3 148,500'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, '999S')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'485-'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, '999MI')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'485-'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, '999MI')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'485 '</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'FM999MI')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'PL999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'+485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'SG999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'+485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, 'SG999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'-485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, '9SG99')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'4-85'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(-485, '999PR')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'<485>'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'L999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'DM 485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'RN')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' CDLXXXV'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, 'FMRN')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'CDLXXXV'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(5.2, 'FMRN')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'V'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(482, '999th')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 482nd'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485, '"Good number:"999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'Good number: 485'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(485.8, '"Pre:"999" Post:" .999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>'Pre: 485 Post: .800'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(12, '99V999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 12000'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(12.4, '99V999')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 12400'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(12.45, '99V9')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 125'</TT
></TD
></TR
><TR
><TD
><TT
CLASS="LITERAL"
>to_char(0.0004859, '9.99EEEE')</TT
></TD
><TD
><TT
CLASS="LITERAL"
>' 4.86e-04'</TT
></TD
></TR
></TBODY
></TABLE
></DIV
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>Pattern Matching</TD
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