ASP and SQLServer time processing method I

In the development of database applications, processing time problems are often encountered, such as querying records at a specified time. Next we will discuss these common problems with your own experience.
First, we will introduce the usage of several major functions for processing time in SQL Server:
    
    
Getdate () function: Gets the current date and time of the system. The return value is of the datetime type.
Usage: getdate ()
Example:
Select getdate () as dte, dateadd (day,-1, getdate () as nowdat
Output result:
Dte nowdat
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19:13:10. 083 19:13:10. 083
    
(1 row (s) affected)
    
Datepart () function: returns the specified part of the time in integer format.
Usage: datepart (datepart, date)
Parameter description: the part of the time to be returned for datepart. Values include year, month, day, hour, and minute.
Date is the specified time.
Example:
Select datepart (month, GETDATE () AS 'month number'
Output result:
Month Number
------------
11
    
(1 row (s) affected)
    
Dateadd () function: adds an integer to the specified part of the specified time to return a new time value.
Usage: dateadd (datepart, number, date)
Parameter description: datepart (same as above)
Date (same as above)
The value to be added by number. It is an integer that can be positive or negative. A positive value returns the time value after date, and a negative value returns the date.
Previous time value