Posted on 2007-07-13 19:46 
kooyee 阅读(3005) 
评论(0)  编辑  收藏  所属分类: 
Database数据库技术 
			 
			
		 
		调用到 to_date() function
 update table
update table 
 set column=to_date('17002000','HH24MIYYYY')
set column=to_date('17002000','HH24MIYYYY')
    or
    set column=to_date('17:002000','HH24:MIYYYY')
select statement (sysdate database的系统中的时间)
 select * from table where month=to_date(SYSDATE', 'MM') //to_date() return month
select * from table where month=to_date(SYSDATE', 'MM') //to_date() return month
   SELECT TO_CHAR(SYSDATE, 'ddMM') FROM dual; //return day and month in charto_date( string1, [ format_mask ], [ nls_language ] )
    
        
            | 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. | 
    
For example:
    
        
            | 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. |