Queries the previous Sunday (Sunday is first day) SQL statement for the week on which the given date is located

Queries the previous Sunday (Sunday is first day) SQL statement for the week on which the given date is located

DECLARE @date datetime
Set @date = GETDATE ()
--Train of thought: The current Diary of the Week in Sunday minus 1 weeks
The return value of--datepart (weekday,date) is related to @ @datefirst
Set Datefirst 7-or set to American English set language us_english; (Sunday is the first day)
Select DATEADD (Week,-1,dateadd (Day,1-datepart (Weekday, @date), @date)) as ' the first day of last week, Sunday '
--One week equals 7 days.
Select DATEADD (Day,-7,dateadd (Day,1-datepart (Weekday, @date), @date)) as ' the first day of last week, Sunday '
--Simplifying
Select DATEADD (Day,-6-datepart (Weekday, @date), @date) as ' the first day of last week, Sunday '
--Last Sunday, nothing to do with SQL Server language version or @ @datefirst
Select DATEADD (Week,-1+datediff (week,-1, @date), -1) as ' last Sunday '
--or
Select DATEADD (Week,datediff (week,6, @date), -1) as ' last Sunday '
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