orecle To_Date()日期操作函数

作者:袖梨 2022-06-29

先看to_date()函数的语法

to_date( string1, [ format_mask ], [ nls_language ] )

参考表

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
RRRR Accepts a 2-digit year and returns a 4-digit year.
A value between 0-49 will return a 20xx year.
A value between 50-99 will return a 19xx year.
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. Use a value from 1 to 9 after FF to indicate the number of digits in the fractional seconds. For example, 'FF4'.
AM, A.M., PM, or P.M. Meridian indicator
AD or A.D AD indicator
BC or B.C. BC indicator
TZD Daylight savings information. For example, 'PST'
TZH Time zone hour.
TZM Time zone minute.
TZR Time zone region.

可用于 Oracle 8i, Oracle 9i, Oracle 10g, Oracle 11g

例子

 代码如下 复制代码

to_date('2003/07/09', 'yyyy/mm/dd') would return a date value of July 9, 2003.
to_date('070903', 'MMDDYY') would return a date value of July 9, 2003.
to_date('20020315', 'yyyymmdd') would return a date value of Mar 15, 2002.

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