The Postgres Plus Advanced Server 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 3-22 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 string template that defines the output or input format.
Table 3-22 Formatting Functions
Function |
Return Type |
Description |
Example |
Result |
TO_CHAR(DATE [, format ]) |
VARCHAR2 |
Convert a date/time to a string with output, format. If omitted default format is DD-MON-YY. |
TO_CHAR(SYSDATE, 'MM/DD/YYYY HH12:MI:SS AM') |
07/25/2007 09:43:02 AM |
TO_CHAR(INTEGER [, format ]) |
CLOB |
Convert an integer to a string with output, format |
TO_CHAR(2412, '999,999S') |
2,412+ |
TO_CHAR(NUMBER [, format ]) |
CLOB |
Convert a decimal number to a string with output, format |
TO_CHAR(10125.35, '999,999.99') |
10,125.35 |
TO_CHAR(DOUBLE PRECISION, format) |
CLOB |
Convert a floating-point number to a string with output, format |
TO_CHAR(CAST(123.5282 AS REAL), '999.99') |
123.53 |
TO_DATE(string [, format ]) |
DATE |
Convert a date formatted string to a DATE data type |
TO_DATE('2007-07-04 13:39:10', 'YYYY-MM-DD HH24:MI:SS') |
04-JUL-07 13:39:10 |
TO_NUMBER(string [, format ]) |
NUMBER |
Convert a number formatted string to a NUMBER data type |
TO_NUMBER('2,412-', '999,999S') |
-2412 |
TO_TIMESTAMP(string, format) |
TIMESTAMP |
Convert a timestamp formatted string to a TIMESTAMP data type |
TO_TIMESTAMP('05 Dec 2000 08:30:25 pm', 'DD Mon YYYY hh12:mi:ss pm') |
05-DEC-00 20:30:25 |
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.
The following table shows the template patterns available for formatting date values using the TO_CHAR and TO_DATE functions.
Table 3-23 Template Date/Time Format Patterns
Pattern |
Description |
HH |
Hour of day (01-12) |
HH12 |
Hour of day (01-12) |
HH24 |
Hour of day (00-23) |
MI |
Minute (00-59) |
SS |
Second (00-59) |
SSSSS |
Seconds past midnight (0-86399) |
AM or A.M. or PM or P.M. |
Meridian indicator (uppercase) |
am or a.m. or pm or p.m. |
Meridian indicator (lowercase) |
Y,YYY |
Year (4 and more digits) with comma |
YEAR |
Year (spelled out) |
SYEAR |
Year (spelled out) (BC dates prefixed by a minus sign) |
YYYY |
Year (4 and more digits) |
SYYYY |
Year (4 and more digits) (BC dates prefixed by a minus sign) |
YYY |
Last 3 digits of year |
YY |
Last 2 digits of year |
Y |
Last digit of year |
IYYY |
ISO year (4 and more digits) |
IYY |
Last 3 digits of ISO year |
IY |
Last 2 digits of ISO year |
I |
Last 1 digit of ISO year |
BC or B.C. or AD or A.D. |
Era indicator (uppercase) |
bc or b.c. or ad or a.d. |
Era indicator (lowercase) |
MONTH |
Full uppercase month name |
Month |
Full mixed-case month name |
month |
Full lowercase month name |
MON |
Abbreviated uppercase month name (3 chars in English, localized lengths vary) |
Mon |
Abbreviated mixed-case month name (3 chars in English, localized lengths vary) |
mon |
Abbreviated lowercase month name (3 chars in English, localized lengths vary) |
MM |
Month number (01-12) |
DAY |
Full uppercase day name |
Day |
Full mixed-case day name |
day |
Full lowercase day name |
DY |
Abbreviated uppercase day name (3 chars in English, localized lengths vary) |
Dy |
Abbreviated mixed-case day name (3 chars in English, localized lengths vary) |
dy |
Abbreviated lowercase day name (3 chars in English, localized lengths vary) |
DDD |
Day of year (001-366) |
DD |
Day of month (01-31) |
D |
Day of week (1-7; Sunday is 1) |
W |
Week of month (1-5) (The first week starts on the first day of the month) |
WW |
Week number of year (1-53) (The first week starts on the first day of the year) |
IW |
ISO week number of year; the first Thursday of the new year is in week 1 |
CC |
Century (2 digits); the 21st century starts on 2001-01-01 |
SCC |
Same as CC except BC dates are prefixed by a minus sign |
J |
Julian Day (days since January 1, 4712 BC) |
Q |
Quarter |
RM |
Month in Roman numerals (I-XII; I=January) (uppercase) |
rm |
Month in Roman numerals (i-xii; i=January) (lowercase) |
RR |
First 2 digits of the year when given only the last 2 digits of the year. Result is based upon an algorithm using the current year and the given 2-digit year. The first 2 digits of the given 2-digit year will be the same as the first 2 digits of the current year with the following exceptions: If the given 2-digit year is < 50 and the last 2 digits of the current year is >= 50, then the first 2 digits for the given year is 1 greater than the first 2 digits of the current year. If the given 2-digit year is >= 50 and the last 2 digits of the current year is < 50, then the first 2 digits for the given year is 1 less than the first 2 digits of the current year. |
RRRR |
Only affects TO_DATE function. Allows specification of 2-digit or 4-digit year. If 2-digit year given, then returns first 2 digits of year like RR format. If 4-digit year given, returns the given 4-digit year. |
Certain modifiers may be applied to any template pattern to alter its behavior. For example, FMMonth is the Month pattern with the FM modifier. The following table shows the modifier patterns for date/time formatting.
Table 3-24 Template Pattern Modifiers for Date/Time Formatting
Modifier |
Description |
Example |
FM prefix |
Fill mode (suppress padding blanks and zeros) |
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 |
DDSP |
Usage notes for date/time formatting:
● FM suppresses leading zeroes and trailing blanks that would otherwise be added to make the output of a pattern 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.
● In conversions from string to timestamp or date, the CC field is ignored if there is a YYY, YYYY or Y,YYY field. If CC is used with YY or Y then the year is computed as (CC-1)*100+YY.
The following table shows the template patterns available for formatting numeric values.
Table 3-25 Template Patterns for Numeric Formatting
Pattern |
Description |
9 |
Value with the specified number of digits |
0 |
Value with leading zeroes |
. (period) |
Decimal point |
, (comma) |
Group (thousand) separator |
$ |
Dollar sign |
PR |
Negative value in angle brackets |
S |
Sign anchored to number (uses locale) |
L |
Currency symbol (uses locale) |
D |
Decimal point (uses locale) |
G |
Group separator (uses locale) |
MI |
Minus sign specified in right-most position (if number < 0) |
RN or rn |
Roman numeral (input between 1 and 3999) |
V |
Shift specified number of digits (see notes) |
Usage notes for numeric formatting:
● 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.
V effectively multiplies the input values by 10n, 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.)
The following table shows some examples of the use of the TO_CHAR and TO_DATE functions.
Table 3-26 TO_CHAR Examples
Expression |
Result |
TO_CHAR(CURRENT_TIMESTAMP, 'Day, DD HH12:MI:SS') |
'Tuesday , 06 05:39:18' |
TO_CHAR(CURRENT_TIMESTAMP, 'FMDay, FMDD HH12:MI:SS') |
'Tuesday, 6 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(1485, '9G999') |
' 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(148.5, '999D999') |
' 148.500' |
TO_CHAR(3148.5, '9G999D999') |
' 3,148.500' |
TO_CHAR(-485, '999S') |
'485-' |
TO_CHAR(-485, '999MI') |
'485-' |
TO_CHAR(485, '999MI') |
'485 ' |
TO_CHAR(485, 'FM999MI') |
'485' |
TO_CHAR(-485, '999PR') |
'<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' |
