SQL，如何循环使用每个日期列表作为过程的参数？

Question

我有一个接收特定日期作为参数的程序即 Exec ProcDB '20150428'

我经常需要运行这个过程很多日期，通常我重新输入 Exec ProcDB 'date1' GO Exec ProcDB 'date2'go... .. 我觉得不聪明，所以

我可以使用 Select 不同的 [dates] From Table1 Order By [dates].

获取有效的日期列表

所以我想创建一个接收 Start_Dt 和 End_Dt 的新过程它循环所有日期，我的 select 不同 returns 其中包括 Start_Dt 和 End_Dt.

ie something like:

Create ProcDBlist Start_Dt as date, End_Dt as date
For each date in: Select Distinct [date] from [table1] where [date] >= @Start_Dt and [date] <= @End_dt
Do: Exec ProcDB 'Date n'
End

更新：

最终解决方案：

Create procedure [dbo].[ProcessDBRange] (@Start_dt as varchar(15) =null, @End_dt as varchar(15) =null)
As
Begin
DECLARE @date as varchar(15)

DECLARE Cursor_ProcessDB CURSOR FOR
    Select Distinct Convert(varchar(15), [date], 112) as [date]
    From [Prices]
    Where [date] >= @Start_dt and [date] <= @End_dt
    Order By [date]

OPEN Cursor_ProcessDB

FETCH next FROM Cursor_ProcessDB
INTO @date

WHILE @@FETCH_STATUS = 0

BEGIN

Exec ProcessDB @date

FETCH next FROM Cursor_ProcessDB
INTO @date

END
CLOSE Cursor_ProcessDB
DEALLOCATE Cursor_ProcessDB
End

Answer 1

这可以通过使用 cursor.
基本上，它是这样的：

DECLARE @Date datetime -- a local variable to get the cursor's result

DECLARE DatesCursor CURSOR FOR
  Select Distinct [dates] where [dates] between @Start_Dt and @End_Dt From Table1 Order By [dates]. -- the query that the cursor iterate on

OPEN DatesCursor
FETCH NEXT FROM DatesCursor INTO @Date 
WHILE @@FETCH_STATUS = 0 -- this will be 0 as long as the cursor returns a result
  BEGIN
    Exec ProcDB @Date
    FETCH NEXT FROM DatesCursor INTO @Date -- don't forget to fetch the next result inside the loop as well!
  END
-- cleanup - Very important!
CLOSE DatesCursor 
DEALLOCATE DatesCursor

编辑
我刚刚阅读了 link that zimdanen 给你的评论，我必须说我认为在这种情况下它可能比使用游标更好。

编辑#2

首先，将OPEN sub改为OPEN cursor_name。其次，使用 CONVERT 将日期作为字符串获取。确保您使用正确的样式进行转换，否则您很容易得到不正确的日期 and/or 异常。

Answer 2

您将需要使用游标。我相信这是一个很好的资源：http://www.codeproject.com/Tips/277847/How-to-use-Cursor-in-Sql

我试着用你提供的信息做了一个例子。

DECLARE @Start_dt DATE;
DECLARE @End_dt DATE;
DECLARE @date DATE;

DECLARE cursor_name CURSOR FOR
    SELECT DISTINCT Date
    FROM [table1]
    WHERE Date >= @Start__Dt 
        and Date <= @End__Dt
    ORDER BY Date

OPEN cursor_name

FETCH next FROM cursor_name
INTO @date

WHILE @@FETCH_STATUS = 0

BEGIN

DECLARE @date2 VARCHAR(15)
SET @date2 = (CAST ( @date AS varchar(15) ))

Exec ProcdB date_parameter_name = @date2     

FETCH next FROM cursor_name
INTO @date

END
CLOSE cursor_name
DEALLOCATE cursor_name

Answer 3

你可以用光标来完成。您也可以更改 proc 以接收 2 个参数 @sd date, @ed date 然后在 proc 中执行循环：

alter procedure procDB
@sd date,
@ed date
as
begin
    while @sd <= @ed
    begin
        --do your staff

        set @sd = dateadd(dd, 1, @sd)
    end    
end

SQL，如何循环使用每个日期列表作为过程的参数？

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