sql日期转换（国外英文资料）.doc

sql日期转换（国外英文资料） Select convert (varchar (10), getdate (), 120) Current system date, time The select getdate () Dateadd will return the new datetime value by adding a period of time to the specified date For example: add 2 days to the date Select dateadd (day, 2, 2004-10-15) - return: 2004-10-17 00:00.00 Datediff returns the date and time boundary of the two specified dates. Select datediff (day, 2004-09-01, 2004-09-18) - returns: 17 The datepart returns an integer that represents the specified date of the specified date. SELECT DATEPART (month, 2004-10-15) - returns 10 Datename returns a string that represents the specified date part of the specified date SELECT datename (weekday, 2004-10-15) -- return: Friday Day (), month (), year () -- can be controlled by the datepart Select current date = convert (varchar (10), getdate (), 120) Current time = convert (varchar (8), getdate (), 114) Select datename (dw, 2004-10-15) Select the first week of the year = datename (week, 2004-10-15) Today is weekday = datename (weekday, 2004-10-15) Function parameters/functions GetDate () returns the current date and time of the system DateDiff (interval, date1 and date2) In an interval, the difference between date2 and date1 is returned date2-date1 The DateAdd (interval, number, date) is specified by the interval, plus the date after the number The DatePart (interval, date) returns the integer value of the part corresponding to the date in date The DateName (interval, date) returns date, and the interval specifies the string name corresponding to the section The setting of the parameter interval is as follows: Value indented (Sql Server) Access and ASP instructions Year Yy yyy 1753 ~ 9999 Quarter Qq q 1 ~ 4 Month Mm m Month 1 ~ 12 Day of year, the number of days of the year, the first of the year, 1-366 Day Dd d Day, 1-31 Weekday Dw w w weekly, the first day of the week 1-7 Week Wk ww Week, the first weeks of the year 0 ~ 51 Hour Hh h time 0 to 23 Minute Mi n minutes 0 to 59 Second S