SQL变量日期减去一年

Question

我有一个存储过程，它有一个日期（YYYYMDD）的用户输入。

为了构建查询的最后一部分，我需要获得12个月前输入的日期。

我尝试了一些不同的方法，比如将其转换为datetime或dateadd函数，但仍然没有成功：下面是我的代码片段：

@DateSelected datetime=null,
@year int=null,
@week int=null,
@DayOfWeek int=null,
@DateSelectedLastYear datetime=null
--@Day int=null
as
begin
    --if date parms are null get current week and year
    if (@DateSelected is null)
        begin
            select @Year=year_number,@Week=week_number,@DayOfWeek=day_of_week from infrastructure..calendar
            where calendar_date=DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()-1))
        end
    else
    begin
        select @Year=year_number,@Week=week_number,@DayOfWeek=day_of_week from infrastructure..calendar
        where calendar_date=@DateSelected
    end
    begin
    Select
         @DateSelectedLastYear = DATEADD(YYYY,-1,@DateSelected)
    end

Answer 1

试试这个：

select dateadd(year, -1, getdate())

Answer 2

试试这个

@DateSelected datetime=null,
@year int=null,
@week int=null,
@DayOfWeek int=null,
@DateSelectedLastYear datetime=null
--@Day int=null
as
begin
    --if date parms are null get current week and year
    if (@DateSelected is null)
        begin
            select @Year=year_number,@Week=week_number,@DayOfWeek=day_of_week from     infrastructure..calendar
            where calendar_date=DATEADD(dd, 0, DATEDIFF(dd, 0, GETDATE()-1))
        end
    else
    begin
        select @Year=year_number,@Week=week_number,@DayOfWeek=day_of_week from     infrastructure..calendar
        where calendar_date=@DateSelected
    end
    begin
    Select
        @DateSelectedLastYear = DATEADD(YEAR,-1,@DateSelected)
   end