Returns the number of whole days between two specified TDateTime values.Unit 天数: DateUtilsCategorydatetime routinesDelphi syntax:function DaysBetween(const ANow, AThen: TDateTime): Integer;DescriptionCall DaysBetween to obtain the difference, in days, between two TDateTime values.DaysBetween counts only whole days. Thus, DaysBetween reports the difference between Dec 31, 1999 11:59 PM and Jan 1, 2000 11:58 PM as 0 because the difference is one minute short of an entire day. 如果是SQL SERVER的话,时分秒是去掉的,实在是讨厌时分秒,用字符字段代替时间字段!
2,直接相减
天数:
DateUtilsCategorydatetime routinesDelphi syntax:function DaysBetween(const ANow, AThen: TDateTime): Integer;DescriptionCall DaysBetween to obtain the difference, in days, between two TDateTime values.DaysBetween counts only whole days. Thus, DaysBetween reports the difference between Dec 31, 1999 11:59 PM and Jan 1, 2000 11:58 PM as 0 because the difference is one minute short of an entire day.
如果是SQL SERVER的话,时分秒是去掉的,实在是讨厌时分秒,用字符字段代替时间字段!
如果是SQL SERVER的话,时分秒是去不掉的,实在是讨厌时分秒,用字符字段代替时间字段!
2.给你函数:
function DayDiff( d1, d2 : TDate ):integer;
var
nYear1, nMonth1, nDay1 : Word;
nYear2, nMonth2, nDay2 : Word;
begin
DecodeDate( d1, nYear1, nMonth1, nDay1 );
DecodeDate( d2, nYear2, nMonth2, nDay2 ); result := Trunc( EncodeDate(nYear1, nMonth1, nDay1) -
EncodeDate( nYear2, nMonth2, nDay2 ) );
end;