Preamble
PostgreSQL to_char function converts a number or date to a string.
Syntax of to_char function in PostgreSQL
to_char( value, format_mask )
Parameters and function arguments
- value – A number, a date to be converted to a string.
- format_mask – The format that will be used to convert the value to a string. The format_mask is different from whether you convert numbers or dates. Let’s have a look.
- WITH NUMBERS – With format_mask numbers can be one of the following and can be used in many combinations:
| Parameter | Explanation |
| 9 | Value (without initial zeroes) |
| 0 | Value (with leading zeros) |
| . | Decimal |
| , | Group splitter |
| PR | A negative value in angle brackets |
| С | Symbol |
| L | Symbol of currency |
| D | Decimal |
| G | Group splitter |
| MI | Minus sign (for negative numbers) |
| PL | Sign plus (for positive numbers) |
| SG | A plus/minus sign (for positive and negative numbers) |
| RN | Roman numerals |
| TH | Serial number suffix |
| th | Serial number suffix |
| V | Shift in numbers |
| EEEE | Scientific notation |
With dates
With dates, format_mask can be one of the following and can be used in many combinations.
| Parameter | Explanation |
| YYYY | 4-digit year |
| Y,YYY | 4-digit semicolon year |
| YYY YY Y |
Last 3, 2 or 1 digit (and) years |
| IYYY | The 4-digit year according to ISO standard |
| IYY IY I |
Last 3, 2 or 1 digit(s) of ISO year |
| Q | A quarter of the year (1, 2, 3, 4; JAN-MAR = 1) |
| ММ | Month (01-12; JAN = 01) |
| MON | Abbreviated name of the month in upper case |
| Mon | Abbreviated name of the month with a capital letter |
| mon | Abbreviated name of the month in lower case |
| MONTH | The name of the month in capital letters, completed with spaces up to 9 characters long |
| Month | The name of the month with a capital letter, supplemented with spaces up to 9 characters long |
| month | The name of the month in lowercase letters, supplemented with spaces up to 9 characters long |
| RM | One month with Roman numerals |
| rm | Month in lowercase Roman numerals |
| WW | Week of the year (1-53), where week 1 begins on the first day of the year |
| W | Week of the month (1-5), where week 1 begins on the first day of the month |
| IW | ISO Week of the year (01-53) |
| DAY | The name of the day in capital letters, completed with spaces up to 9 characters long |
| Day | The name of the day with a capital letter, completed with spaces up to 9 characters long |
| day | The name of the day in lowercase letters, completed with spaces up to 9 characters long |
| DY | Abbreviated name of the day in upper case |
| Dy | Abbreviated name of the day with a capital letter |
| dy | Abbreviated name of the day in lowercase letters |
| DDD | Day of the year (1-366) |
| IDDD | Day of the year based on ISO year |
| DD | Day of the month (01-31) |
| D | Day of the week (1-7, where 1 = Sunday, 7 = Saturday) |
| ID | Day of the week based on ISO year (1-7, where 1 = Monday, 7 = Sunday) |
| J | Julian day; the number of days from midnight November 24, 4714 BC. |
| HH | One o’clock of the day (01-12) |
| HH12 | One o’clock of the day (01-12) |
| HH24 | One o’clock of the day (00-23) |
| MI | One minute (00-59) |
| SS | One second (00-59) |
| MS | Millisecond (000-999) |
| US | Microsecond (000000-999999) |
| SSSS | Seconds after midnight (0-86399) |
| am, AM, pm, or PM | Meridian Indicator |
| a.m., A.M., p.m., or P.M. | Meridian Indicator |
| ad, AD, a.d., or A.D | AD indicator |
| bc, BC, b.c., or B.C. | BC Indicator |
| TZ | Name of the time zone in upper case |
| tz | Name of the time zone in lower case |
| CC | 2-digit century |
The to_char function can be used in future versions of PostgreSQL
PostgreSQL 11, PostgreSQL 10, PostgreSQL 9.6, PostgreSQL 9.5, PostgreSQL 9.4, PostgreSQL 9.3, PostgreSQL 9.2, PostgreSQL 9.1, PostgreSQL 9.0, PostgreSQL 8.4.
Let’s take a look at some examples of to_char functions to see how to_char can be used in PostgreSQL.
Example with numbers
Below are numerical examples of the to_char function.
SELECT to_char(1918, '9999.99');
--Result: 1918.00
SELECT to_char(1814.7, '9G999.99');
--Result: 1,814.70
SELECT to_char(1810.7, 'L9G999.99'); -Result: 1,814.70;
--Result: $ 1,810.70
SELECT to_char(1810.7, 'L9G999');
--Result: $ 1,811
SELECT to_char(141, '9 9 9');
--Result: 1 4 1
SELECT to_char(123, '00999');
--Result: 00123
Example with dates
Below are examples of the dates of the to_char function.
SELECT to_char(date '2019-04-23', 'YYYY/MM/DD');
--Result: 2019/04/23
SELECT to_char(date '2019-04-23', 'MMDDYY');
--Result: 042319
SELECT to_char(date '2019-04-23', 'Month DD, YYYYY');
--Result: April 23, 2019
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