oracle to_char()函數用法詳解

TO_CHAR函數的Oracle / PLSQL，數字或日期轉換為一個字串。

to_char函數的文法是：
to_char( value, [ format_mask ], [ nls_language ] )

值可以是數字或日期將被轉換為一個字串。

format_mask是可選的。這是將要使用的格式轉換成一個字串值。

NLS_LANGUAGE是可選的。這是免入息審查貸款計劃的語言，用於轉換為字串的值。

Applies To:

代碼如下	複製代碼
Oracle 8i, Oracle 9i, Oracle 10g, Oracle 11g

執行個體

代碼如下	複製代碼
to_char(1210.73, '9999.9') would return '1210.7' to_char(1210.73, '9,999.99') would return '1,210.73' to_char(1210.73, '$9,999.00') would return '$1,210.73' to_char(21, '000099') would return '000021'

日期執行個體

下面是一個有效參數列表to_char函數是用來轉換為一個字串的日期。這些參數可用於在多種組合。

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.

 

代碼如下	複製代碼
to_char(sysdate, 'yyyy/mm/dd'); would return '2003/07/09' to_char(sysdate, 'Month DD, YYYY'); would return 'July 09, 2003' to_char(sysdate, 'FMMonth DD, YYYY'); would return 'July 9, 2003' to_char(sysdate, 'MON DDth, YYYY'); would return 'JUL 09TH, 2003' to_char(sysdate, 'FMMON DDth, YYYY'); would return 'JUL 9TH, 2003' to_char(sysdate, 'FMMon ddth, YYYY'); would return 'Jul 9th, 2003'

你會發現，在一些例子中，format_mask參數與“FM”開始。這意味著，零和空格被抑制。這在下面的例子可以看出。

代碼如下	複製代碼
to_char(sysdate, 'FMMonth DD, YYYY'); would return 'July 9, 2003' to_char(sysdate, 'FMMON DDth, YYYY'); would return 'JUL 9TH, 2003' to_char(sysdate, 'FMMon ddth, YYYY'); would return 'Jul 9th, 2003'