to_char.doc

TO_CHAR Function With Date Date Format Model Elements YYYY FULL year in numbers YEAR year spelled out MM 2-digit value for month MONTH Full name of the month MON Name of month,three-letter abbreviation RM Ruman numeral month DY 3-letter abbreviation of the day of the week DAY Full name of the day SCC or CC Century ;S prefixes BC date with - Years in dates YYYY or SYYYY Year ;S prefixes BC date with - YYY or YY or Y Last 3,2,1 digit(s) of year Y,YYY Year with comma in this position IYYY or IYY or IY or I 4,3,2 or 1 digit year based on the ISO standard SYEAR or YEAR year spelled out;S prefixes BC date with - BC or AD BC/AD indicator B.C. or A.D. BC/AD indicator with periods Q Quarter of year WW or W Week of the year or month DDD or DD or D Day of year,month,week J Julian day;the number of days since 31 december 4713 BC AM or PM Meridian indicator A.M. or P.M. Meridian indicator with periods HH or HH12 or HH24 Hour of day or hour(12) or hour(24) MI Minute(0-59) SS Second(0-59) SSSSS Seconds past midnight(0-86399) TH Ordinal Number SP Spelled-out number THSP or SPTH Spelled-out Ordinal number /., Punctuation is reproduced in the result of the Quoted String is reproduced in the result *：fm前缀用来去掉0 如：Select to_char(to_date(2007-10-05,yyyy-mm-dd),fmdd) From dual; 结果为：5 Select to_char(to_date(2007-10-05,yyyy-mm-dd),dd) From dual; 结果为：05 TO_CHAR Function With Numbers 例：Select to_char(0.99,fm999.99) From dual; 结果： .99（fm去掉左边空格） Select to_char(0.99,fm990.99) From dual; 结果： 0.99 例：To_char 和 to_date 组合用法 to_char 用于日期转换成字符串时, fm 去掉前导0, 如果格式穿里边重复使用 fm 会发生什么事情?请看:SQL select to_char(sysdate,yy-mm-dd) from dual;TO_CHAR(SYSDATE,YY-MM-DD)---------------------------08-07-16SQL select to_char(sysdate,fmyy-mm-dd) from dual;TO_CHAR(SYSDATE,FMYY-MM-DD)-----------------------------8-7-16SQL select to_char(sysdate,yy-fmmm-dd) from dual;TO_CHAR(SYSDATE,YY-FMMM-DD)----------------------------