Using DATEPART to get a week

Take the date 2017-12-11 (Monday) as an example

one or one-like usage

Select DATEPART (Weekday, ' 2017-12-11 ')

Results: 2

Description: Due to MS SQL default Sunday is the 1th day of one weeks, so 2017-12-11 Monday on the 2nd day of one weeks. So analogy: 1. 7 represents the Sunday. Saturday

Ii. setting Monday as the 1th day of one weeks

Set Datefirst 1 -This sentence will be set in Monday for the 1th day of one weeks.

Select DATEPART (Weekday, ' 2017-12-11 ')

Results: 1

Description: Set Datefirst 1 can be set to Monday one weeks on the 1th day, so 2017-12-11 Monday on the 1th day of one weeks. So analogy: 1. 7 represents the Monday. Sunday.

three, the use of SET Datefirst

Syntax: SET datefirst {number | @number_var} 

Parameters
Number | @number_var
indicates an integer for the first day of the week. Can be one of the following values.

The first day of the week is &NBSP
1 week  
2 Tuesday  
3 week three  
4 week four  
5 Friday  
6 Saturday  < br> 7 Week day (default, U.S. English)
  
Description:  
To view the current settings of the set Datefirst, use the @ @DATEFIRST function. The settings for the

set Datefirst are set at execution or Run-time, not at parse time.