| | The EnterpriseDB 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.
Table 8-19 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.
Table 8-19. Formatting Functions | Function | Return Type | Description | Example |
|---|
to_char(DATE, VARCHAR) | VARCHAR | convert a value of DATE datatype to VARCHAR datatype | to_char(sysdate, 'HH12:MI:SS') | to_char(INT, VARCHAR) | VARCHAR | convert INTEGER to VARCHAR | to_char(125, '999') | to_char(DOUBLE PRECISION,
VARCHAR) | VARCHAR | convert REAL/DOUBLE PRECISION to VARCHAR | to_char(125.8::real, '999D9') | to_char(NUMERIC, VARCHAR) | VARCHAR | convert >NUMERIC to VARCHAR | to_char(-125.8, '999D99S') | to_date(VARCHAR, VARCHAR) | TIMESTAMP | TIMESTAMP is used to allow compatibility with Redwood Dates. Redwood dates return TIME along
with DATE | to_date('05 Dec 2000', 'DD Mon YYYY') | to_timestamp(VARCHAR, VARCHAR) | TIMESTAMP | convert VARCHAR to TIME STAMP | to_timestamp('05 Dec 2000', 'DD Mon YYYY') | to_number(VARCHAR, VARCHAR) | NUMERIC | convert VARCHAR to NUMERIC | to_number('12,454.8-', '99G999D9S') |
In an output template string (for to_char), there are certain patterns that are
recognized and replaced with appropriately-formatted data from the value
to be formatted. Any text that is not a template pattern is simply
copied verbatim. Similarly, in an input template string (for anything but to_char), template patterns
identify the parts of the input data string to be looked at and the
values to be found there.
Table 8-20 shows the
template patterns available for formatting date values using the
to_char and to_date functions.
Table 8-20. Template Date/Time Format Patterns for the to_char and to_date Functions | Pattern | Description |
|---|
| AD | AD indicator without periods. | | A.D. | AD indicator with periods. | | AM | Meridian indicator without periods. | | A.M. | Meridian indicator with periods. | | BC | BC indicator without periods. | | B.C. | BC indicator with periods. | | CC | One greater than the first two digits of a four-digit year; | | SCC | One greater than the first two digits of a four-digit year; "S" prefixes BC dates with "-" | | D | Day of week (1-7). | | DAY | Name of day, padded with blanks to length of 9 characters. | | DD | Day of month (1-31). | | DDD | Day of year (1-366). | | DY | Abbreviated name of day. | | E | Abbreviated era name (Japanese Imperial, ROC Official, and Thai Buddha calendars). | | EE | Full era name (Japanese Imperial, ROC Official, and Thai Buddha calendars). | | FF [1..9] | Fractional seconds; no radix character is printed (use the X format element to add the radix character).
Use the numbers 1 to 9 after FF to specify the number of digits in the fractional second portion of
the date value returned. If you do not specify a digit, then EnterpriseDB uses the precision
specified for the date datatype or the datatype's default precision.
Example
SELECT TO_CHAR(SYSTIMESTAMP, 'HH:MM:SS MS') FROM DUAL;
SELECT TO_CHAR(SYSTIMESTAMP, 'HH:MM:SS US') FROM DUAL;
| | HH | Hour of day (1-12). | | HH12 | Hour of day (1-12). | | HH24 | Hour of day (0-23). | | IW | Week of year (1-52 or 1-53) based on the ISO standard. | | IYY
IY
I
| Last 3, 2, or 1 digit(s) of ISO year. | | IYYY | 4-digit year based on the ISO standard. | | J | Julian day; the number of days since January 1, 4712 BC. Number specified with "J" must be integers. | | MI | Minute (0-59). | | MM | Month (01-12; JAN = 01). | | MON | Abbreviated name of month. | | MONTH | Name of month, padded with blanks to length of 9 characters. | | PM | Meridian indicator without periods. | | P.M. | Meridian indicator with periods. | | Q | Quarter of year (1, 2, 3, 4; JAN-MAR = 1). | | RM | Roman numeral month (I-XII; JAN = I). | | RR | Given a year with 2 digits:
If the year is <50 and the last 2 digits of the current year are >=50,
then the first 2 digits of the returned year are 1 greater than the first 2 digits of the current year.
If the year is >=50 and the last 2 digits of the current year are <50,
then the first 2 digits of the returned year are 1 less than the first 2 digits of the current year.
| | RRRR | Round year. Accepts either 4-digit or 2-digit input.
If 2-digit, provides the same return as RR. If you don't want this functionality,
then simply enter the 4-digit year.
| | SS | Second (0-59). | | SSSSS | Seconds past midnight (0-86399). | | TZD | Daylight savings information. The TZD value is an abbreviated time zone
string with daylight savings information. It must correspond with the
region specified in TZR.
Examples:
PST (for US/Pacific standard time); PDT (for US/Pacific daylight time).
| | TZH | Time zone hour. | | TZM | Time zone minute. | | TZR | Time zone region information. The value must be one of the time zone regions supported in the database. | | WW | Week of year (1-53) where week 1 starts on the first day of the year and continues to the seventh day of the year. | | W | Week of month (1-5) where week 1 starts on the first day of the month and ends on the seventh. | | X | Local radix character. | | Y,YYY | Year with comma in this position. | | YEAR | Year, spelled out | | SYEAR | Year, spelled out; "S" prefixes BC dates with "-". | | YYYY | 4-digit year | | SYYYY | 4-digit year | | YYY
YY
Y
| Last 3, 2, or 1 digit(s) of year. |
Table 8-21shows the format masks that are available for the round function.
Table 8-21. Template Date/Function Patterns for the round Function | Format Mask | Rounds to |
|---|
| CC or SSC | Century | | SYYY, YYYY, YEAR, SYEAR, YYY, YY, or Y | Year (rounds up to next year on July 1) | | IYYY, IYY, IY, or I | Standard ISO year | | Q | Quarter (rounds up on the sixteenth day of the second month of the quarter) | | MONTH, MON, MM, or RM | Month (rounds up on the sixteenth day, which is not necessarily the same as the middle of the month) | | WW | Same day of the week as the first day of the year | | IW | Same day of the week as the first day of the ISO year | | W | Same day of the week as the first day of the month | | DDD, DD, or J | Day | | DAY, DY, or D | Starting day of the week | | HH, HH12, HH24 | Hour | | MI | Minute |
Certain modifiers may be applied to any template pattern to alter its
behavior. For example, FMMonth
is the Month pattern with the
FM modifier.
Table 8-22 shows the
modifier patterns for date/time formatting.
Table 8-22. Template Pattern Modifiers for Date/Time Formatting | Modifier | Description | Example |
|---|
| FM prefix | fill mode (suppress padding blanks and zeroes) | FMMonth | | TH suffix | uppercase ordinal number suffix | DDTH | | th suffix | lowercase ordinal number suffix | DDth | | FX prefix | fixed format global option (see usage notes) | FX Month DD Day | | SP suffix | spell mode (not yet implemented) | DDSP |
Usage notes for the date/time formatting:
FM suppresses leading zeroes and trailing blanks
that would otherwise be added to make the output of a pattern be
fixed-width.
to_timestamp and to_date
skip multiple blank spaces in the input string if the FX option
is not used. FX must be specified as the first item
in the template. For example
to_timestamp('2000 JUN', 'YYYY MON') is correct, but
to_timestamp('2000 JUN', 'FXYYYY MON') returns an error,
because to_timestamp expects one space only.
Ordinary text is allowed in to_char
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
'"Hello Year "YYYY', the YYYY
will be replaced by the year data, but the single Y in Year
will not be.
If you want to have a double quote in the output you must
precede it with a backslash, for example '\\"YYYY
Month\\"'.
(Two backslashes are necessary because the backslash already
has a special meaning in a string constant.)
The YYYY conversion from string to TIMESTAMP or
DATE has a restriction if you use a year with more than 4 digits. You must
use some non-digit character or template after YYYY,
otherwise the year is always interpreted as 4 digits. For example
(with the year 20000):
to_date('200001131', 'YYYYMMDD') will be
interpreted as a 4-digit year; instead use a non-digit
separator after the year, like
to_date('20000-1131', 'YYYY-MMDD') or
to_date('20000Nov31', 'YYYYMonDD').
Millisecond (MS) and microsecond (US)
values in a conversion from string to TIMESTAMP are used as part of the
seconds after the decimal point. For example
to_timestamp('12:3', 'SS:MS') is not 3 milliseconds,
but 300, because the conversion counts it as 12 + 0.3 seconds.
This means for the format SS:MS, the input values
12:3, 12:30, and 12:300 specify the
same number of milliseconds. To get three milliseconds, one must use
12:003, which the conversion counts as
12 + 0.003 = 12.003 seconds.
Here is a more
complex example:
to_timestamp('15:12:02.020.001230', 'HH:MI:SS.MS.US')
is 15 hours, 12 minutes, and 2 seconds + 20 milliseconds +
1230 microseconds = 2.021230 seconds.
Table 8-23 shows the
template patterns available for formatting numeric values.
Table 8-23. Template Patterns for Numeric Formatting | Pattern | Description |
|---|
| 9 | value with the specified number of digits with a leading space
if positive or with a leading minus if negative.
| | 0 | value with leading/trailing zeros | | $ | value with a leading dollar sign | | MI | places a trailing minus sign (-) with a negative value | | D | specifies the location of a decimal point in the returned value | | G | specifies the location of the group separator in the returned value | | L | currency symbol (uses locale) | | D | decimal point (uses locale) | | , (comma) | returns a comma in the specified position. | | . (period) | returns a decimal point, which is a period (.) in the specified position |
Usage notes for the numeric formatting:
A sign formatted using SG, PL, or
MI is not anchored to
the number; for example,
to_char(-12, 'S9999') produces ' -12',
but to_char(-12, 'MI9999') produces '- 12'.
9 results in a value with the same number of
digits as there are 9s. If a digit is
not available it outputs a space.
TH does not convert values less than zero
and does not convert fractional numbers.
PL, SG, and
TH are EnterpriseDB
extensions.
V effectively
multiplies the input values by
10^n, where
n is the number of digits following
V.
to_char does not support the use of
V combined with a decimal point.
(E.g., 99.9V99 is not allowed.)
Table 8-24 shows some
examples of the use of the to_char and
to_date functions.
Table 8-24. to_char and to_date function Examples | Expression | Result |
|---|
| to_char(current_timestamp, 'Day, DD HH12:MI:SS') | 'Tuesday , 06 05:39:18' | | to_char(-0.1, '99.99') | ' -.10' | | to_char(-0.1, 'FM9.99') | '-.1' | | to_char(0.1, '0.9') | ' 0.1' | | to_char(12, '9990999.9') | ' 0012.0' | | to_char(12, 'FM9990999.9') | '0012.' | | to_char(485, '999') | ' 485' | | to_char(-485, '999') | '-485' | | to_char(1485, '9,999') | ' 1,485' | | to_char(148.5, '999.999') | ' 148.500' | | to_char(148.5, 'FM999.999') | '148.5' | | to_char(148.5, 'FM999.990') | '148.500' | | to_char(-485, '999S') | '485-' | | to_char(-485, '999MI') | '485-' | | to_char(485, '999MI') | '485 ' | | to_char(485, 'FM999MI') | '485' | | to_char(485, 'L999') | '$ 485 | | to_char(485, 'RN') | ' CDLXXXV' | | to_char(485, 'FMRN') | 'CDLXXXV' | | to_char(5.2, 'FMRN') | 'V' | | to_char(12, '99V999') | ' 12000' | | to_char(12.4, '99V999') | ' 12400' | | to_char(12.45, '99V9') | ' 125' | | to_number(0, '99.9') | '.00' | | to_number(-0.2, '99.9') | '-.20' |
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