SQL datediff calculation time difference

For information about datediff, see:

 

 
Datediff (datepart, startdate, enddate)
 

Datepart

Is part of startdate and enddate of the specified cross-border type. The following table lists all valid datepart parameters. The user-defined equivalent variable is invalid.

Datepart	Abbreviations
Year	YY, yyyy
Quarter	QQ, Q
Month	Mm, m
Dayofyear	Dy, y
Day	DD, d
Week	Wk, WW
Hour	HH
Minute	Mi, n
Second	SS, S
Millisecond	MS
Microsecond	MCS
Nanosecond	NS

Startdate

Is an expression that can be parsedTime,Date,Smalldatetime,Datetime,Datetime2OrDatetimeoffsetValue. Date can be an expression, column expression, user-defined variable, or string text. Subtract startdate from enddate.

To avoid uncertainty, use a four-digit year. For information about the two-digit year, see the two digit year cutoff option.

Enddate

See startdate.

 

 

1. Return two-quarter time difference records

CodeAs follows: if necessary, you can change the time field to the corresponding field in the database.

View code 1 Declare @ startdatetime
2 Declare @ enddatetime
3 Set @ Startdatetime = ' 2011-01-01 '
4 Set @ Enddatetime = ' 2011-07-10 '
5 Select datediff (QQ, @ startdatetime, @ enddatetime)

 

2. Search for orders in the last three months.

The Code is as follows:

View codeDeclare @ startdatetime
Declare @ enddatetime
Set@ Startdatetime='2011-05-01'
Set@ Enddatetime=Getdate ()
Select datediff (M, @ startdatetime, @ enddatetime)

 

3. Return the number of days between the time of the first order and the time of the last order.

 

 

Select datediff (day, (select Min (insdt) from op_order), (select max (insdt) from op_order ))

 

4. Use the getdate () function to obtain the current time,

If getdate () + 1 is used, the result is to add one more day in the current time.

For example:

Getdate (): 2011-08-13 13:53:09. 243

Getdate () + 1: 2011-08-14 13:53:09. 243

As shown above, add 1 directly in the period of time.

 

 

 

 

 

 

 

For details, refer to technet.

: Datediff