Formatting functions of PolarDB for Oracle provide a powerful set of tools for converting various data types (date/time, integer, floating point, and numeric) into formatted strings. These functions can also convert formatted strings into specific data types.
The following table describes these formatting functions. These functions 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.
| Function | Return type | Description | Example | Result |
|---|---|---|---|---|
| TO_CHAR(DATE [, format ]) | VARCHAR2 | Converts a date/time to a string in the format specified by the format argument. If you omit the format argument, the function returns a string in the default format (DD-MON- YY). | TO_CHAR(SYSDATE, 'MM/DD/YYYY HH12:MI:SS AM') | 07/25/2007 09:43:02 AM |
| TO_CHAR(INTEGER [, format ]) | VARCHAR2 | Converts an integer to a string in the format specified by the format argument. | TO_CHAR(2412, '999,999S') | 2,412+ |
| TO_CHAR(NUMBER [, format ]) | VARCHAR2 | Converts a decimal number to a string in the format specified by the format argument. | TO_CHAR(10125.35, '999,999.99') | 10,125.35 |
| TO_CHAR(DOUBLE PRECISION, format) | VARCHAR2 | Converts a floating-point number to a string in the format specified by the format argument. | TO_CHAR(CAST(123.5282 AS REAL), '999.99') | 123.53 |
| TO_DATE(string [, format ]) | DATE | Converts 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 | Converts a number formatted string to a NUMBER data type. | TO_NUMBER('2,412-', '999,999S') | -2412 |
| TO_TIMESTAMP(string, format) | TIMESTAMP | Converts 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 the TO_CHAR function, some specific patterns are recognized and replaced with appropriately-formatted data from the value to be formatted. Any text that is not a template pattern is an exact copy. Similarly, in an input template string (for any function 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 lists the available template patterns for formatting date values by using the TO_CHAR and TO_DATE functions.
| 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 characters in English, localized lengths vary) |
| Mon | Abbreviated mixed-case month name (3 characters in English, localized lengths vary) |
| mon | Abbreviated lowercase month name (3 characters 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 characters in English, localized lengths vary) |
| Dy | Abbreviated mixed-case day name (3 characters in English, localized lengths vary) |
| dy | Abbreviated lowercase day name (3 characters 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 | The first 2 digits of the year when given only the last 2 digits of the year. The
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:
|
| RRRR | Only affects the 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. |
Specific 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 lists
the 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 note) | FX Month DD Day |
| SP suffix | Spell mode | DDSP |
Note
- FM suppresses leading zeros and trailing blanks that would otherwise be added to ensure that the output conforms to a fixed width pattern.
- If the FX option is not used, TO_TIMESTAMP and TO_DATE skip multiple blank spaces in the input string. You must specify FX as the first item in the template. For example, TO_TIMESTAMP('2000 JUN', 'YYYY MON') is valid, but TO_TIMESTAMP('2000 JUN', 'FXYYYY MON') returns an error, because TO_TIMESTAMP only expects one space.
- 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 a YYY, YYYY or Y,YYY field exists. If CC is used with the YY or Y field, the year is computed as (CC-1)*100+YY.
The following table shows the available template patterns for formatting numeric values.
| 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 note) |
Note
- 9 results in a value with the same number of digits as there are 9s. If a digit is not available or specified, a space is output.
- TH does not convert values less than zero or fractional numbers.
V effectively multiplies the input values by 10n (10 to the power of n), where n indicates the number of digits following V. TO_CHAR does not support the use of V combined with a decimal point. (For example, 99.9V99 is not allowed.)
The following table shows some examples about how to use TO_CHAR and TO_DATE.
| 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(4 85, 'FM999MI') | '485' |
| TO_CHAR(-485, '999PR') | '<485>' |
| TO_CHAR(485, 'L999') | '$ 485' |
| TO_CHAR(4 85, 'RN') | ' CDLXXXV' |
| TO_CHAR(4 85, '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' |