ORACLE_TO_CHAR Function

TECHONTHENNTE  WEBSITE:　　https://www.techonthenet.com/oracle/functions/to_char.php

Oracle / PLSQL: TO_CHAR Function

This Oracle tutorial explains how to use the Oracle/PLSQL TO_CHAR function with syntax and examples.

Description

The Oracle/PLSQL TO_CHAR function converts a number or date to a string.

Syntax

The syntax for the TO_CHAR function in Oracle/PLSQL is:

TO_CHAR( value [, format_mask] [, nls_language] )

Parameters or Arguments

value

A number or date that will be converted to a string.

format_mask

Optional. This is the format that will be used to convert value to a string.

nls_language

Optional. This is the nls language used to convert value to a string.

Returns

The TO_CHAR function returns a string value.

Applies To

The TO_CHAR function can be used in the following versions of Oracle/PLSQL:

• Oracle 12c, Oracle 11g, Oracle 10g, Oracle 9i, Oracle 8i

Example

Let's look at some Oracle TO_CHAR function examples and explore how to use the TO_CHAR function in Oracle/PLSQL.

Examples with Numbers

For example:

The following are number examples for the TO_CHAR function.

TO_CHAR(1210.73, '9999.9')
Result: ' 1210.7'

TO_CHAR(-1210.73, '9999.9')
Result: '-1210.7'

TO_CHAR(1210.73, '9,999.99')
Result: ' 1,210.73'

TO_CHAR(1210.73, '$9,999.00')
Result: ' $1,210.73'

TO_CHAR(21, '000099')
Result: ' 000021'

Examples with Dates

The following is a list of valid parameters when the TO_CHAR function is used to convert a date to a string. These parameters can be used in many combinations.

Parameter	Explanation
YEAR	Year, spelled out
YYYY	4-digit year
YYY YY Y	Last 3, 2, or 1 digit(s) of year.
IYY IY I	Last 3, 2, or 1 digit(s) of ISO year.
IYYY	4-digit year based on the ISO standard
Q	Quarter of year (1, 2, 3, 4; JAN-MAR = 1).
MM	Month (01-12; JAN = 01).
MON	Abbreviated name of month.
MONTH	Name of month, padded with blanks to length of 9 characters.
RM	Roman numeral month (I-XII; JAN = I).
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.
IW	Week of year (1-52 or 1-53) based on the ISO standard.
D	Day of week (1-7).
DAY	Name of day.
DD	Day of month (1-31).
DDD	Day of year (1-366).
DY	Abbreviated name of day.
J	Julian day; the number of days since January 1, 4712 BC.
HH	Hour of day (1-12).
HH12	Hour of day (1-12).
HH24	Hour of day (0-23).
MI	Minute (0-59).
SS	Second (0-59).
SSSSS	Seconds past midnight (0-86399).
FF	Fractional seconds.

The following are date examples for the TO_CHAR function.

TO_CHAR(sysdate, 'yyyy/mm/dd')
Result: '2003/07/09'

TO_CHAR(sysdate, 'Month DD, YYYY')
Result: 'July 09, 2003'

TO_CHAR(sysdate, 'FMMonth DD, YYYY')
Result: 'July 9, 2003'

TO_CHAR(sysdate, 'MON DDth, YYYY')
Result: 'JUL 09TH, 2003'

TO_CHAR(sysdate, 'FMMON DDth, YYYY')
Result: 'JUL 9TH, 2003'

TO_CHAR(sysdate, 'FMMon ddth, YYYY')
Result: 'Jul 9th, 2003'

You will notice that in some TO_CHAR function examples, the format_mask parameter begins with "FM". This means that zeros and blanks are suppressed(vt. 镇压,使...止住,禁止. )This can be seen in the examples below.

TO_CHAR(sysdate, 'FMMonth DD, YYYY')
Result: 'July 9, 2003'

TO_CHAR(sysdate, 'FMMON DDth, YYYY')
Result: 'JUL 9TH, 2003'

TO_CHAR(sysdate, 'FMMon ddth, YYYY')
Result: 'Jul 9th, 2003'

The zeros have been suppressed so that the day component shows as "9" as opposed to "09".

Frequently Asked Questions

Question: Why doesn't this sort the days of the week in order?

SELECT ename, hiredate, TO_CHAR((hiredate),'fmDay') "Day"
FROM emp
ORDER BY "Day";

Answer: In the above SQL, the fmDay format mask used in the TO_CHAR function will return the name of the Day and not the numeric value of the day.

To sort the days of the week in order, you need to return the numeric value of the day by using the fmD format mask as follows:

SELECT ename, hiredate, TO_CHAR((hiredate),'fmD') "Day"
FROM emp
ORDER BY "Day";