SQL Date Type

DECLARE @datetime datetime = Current_timestamp, @date date = Current_timestamp, @time time = Current_timestampselect @date Time--2018-06-08 09:01:10.440select @date--2018-06-08select @time--09:01:10.4400000-----------DATEADD () function to add or subtract a specified time interval from a date. ---------------------Select Dateadd (d,1, ' 2018-01-01 00:00:00.000 ')--2018-01-02 00:00:00.000------------DATEDIFF () The function returns a time between two dates. ------------------------------Select Datediff (d, ' 2018-01-01 ', ' 2018-01-02 ')--1--datename returns the string type select GETDATE () as Current date, datename (year, GETDATE ()) as years, Datename (month, GETDATE ()) as month, Datename (day, GETDATE ()) as date, Datename (quarter, GE Tdate ()) as quarter, Datename (DayOfYear, GETDATE ()) as the number of days of the Year, Datename (DW, GETDATE ()) as week, Datename (week, GETDATE ()) as weeks , Datename (Hour, GETDATE ()) as, Datename (minute, GETDATE ()) as, Datename (second, GETDATE ()) as seconds, datename (millisecond , GETDATE ()) as MS Select Datepart (yy,getdate ())--Returns the value type Select Isdate (' 2018-01-32 ')--Determines whether the string is a date, is 1, no 0select year ( GETDATE ()) as year, Month (GETDATE()) as month, Day (GETDATE ()) As date--return value type

SQL Date Type