TO_CHAR(d, fmt) Converts d of date datatype to a value of varchar2 datatype. The format fmt specifies the date format. SQL> -- Convert date and time to character strings SQL> SELECT TO_CHAR(SYSDATE, 'HH24:MI:SS') FROM dual; SQL> -- output: 22:25:15 SQL> SELECT TO_CHAR(SYSDATE, 'DD-Mon-YYYY') FROM dual; SQL> -- output: 04-Nov-2002 SQL> SELECT TO_CHAR(SYSDATE, 'Month DD, YYYY') FROM dual; SQL> -- output: November 04, 2002
Examples - 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'); 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' You will notice that in some examples, the format_mask parameter begins with "FM". This means that zeros and blanks are suppressed. This can be seen in the examples below.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' The zeros have been suppressed so that the day component shows as "9" as opposed to "09".
to_char(date,'yyyy-mm-dd') 其中‘yyyy-mm-dd’是时间格式掩码，可以根据需要设置不同格式，可以包括时间等如：hh mi ss
Converts d of date datatype to a value of varchar2 datatype. The format fmt specifies the date format. SQL> -- Convert date and time to character strings
SQL> SELECT TO_CHAR(SYSDATE, 'HH24:MI:SS') FROM dual;
SQL> -- output: 22:25:15
SQL> SELECT TO_CHAR(SYSDATE, 'DD-Mon-YYYY') FROM dual;
SQL> -- output: 04-Nov-2002
SQL> SELECT TO_CHAR(SYSDATE, 'Month DD, YYYY') FROM dual;
SQL> -- output: November 04, 2002
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'); 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' You will notice that in some examples, the format_mask parameter begins with "FM". This means that zeros and blanks are suppressed. This can be seen in the examples below.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' The zeros have been suppressed so that the day component shows as "9" as opposed to "09".
将它转换成字符串