Date function: Getdate,dateadd,dateiff

--Date function
--getdate (): Gets the current date
--dateadd (interval unit, increment value, source date value): Adds a date value for a specified interval for the specified date
Select DATEADD (Mm,3,getdate ())
Select DATEADD (Mm,-3,getdate ())
--datediff (interval unit, start date, end date) Gets the difference value between two dates
Select DATEDIFF (ss, ' 1990-1-1 ', GETDATE ())
--Query The student information, show the student's name, student number, and age
Select Studentno,studentname,datediff (Yyyy,borndate,getdate ()) from Student
--datename () Gets the string part of the date
Select Datename (Yy,getdate ())
--datepart gets the specified date part
Select DATEPART (Ns,getdate ())

Date function: Getdate,dateadd,dateiff