基于输入参数自动填充日期时间值的SQL表字段

Question

我在我的SQL表中有一个日期时间字段。我创建了一个将count作为变量并为表生成记录的过程。如果计数为5会产生我想要的是，当我提供5作为输入参数表中的日期时间字段应该有这么一个记录插入每一个时间值

12/20/2015 9:00 
12/20/2015 11:00 
12/20/2015 13:00 
12/20/2015 15:00 
12/20/2015 17:00 

自动填充5 records.The逻辑放入表格中，应该添加2小时的时间。

Answer 1

递归CTEs是动态创建记录的一种方式。这里的关键是创建一个锚点（这是CTE中的第一个SELECT，这是您的出发点）。和一个退出检查（这是WHERE子句）。

如果您想一次创建超过100条记录，请阅读MAXRECURSION。

例

DECLARE @RecordsRequired INT = 5; 
DECLARE @BaseDateTime  SMALLDATETIME = GETDATE(); 


WITH [Sample] AS 
    (
     /* This CTE uses recursion to create the required number of 
     * records. 
     */ 
      SELECT 
       1    AS RowNumber, 
       @BaseDateTime AS [DateTime] 

     UNION ALL 

      SELECT 
       RowNumber + 1     AS RowNumber, 
       DATEADD(HOUR, 2, [DateTime]) AS [DateTime] 
      FROM 
       [Sample] 
      WHERE 
       RowNumber < @RecordsRequired 
    ) 
SELECT 
    RowNumber, 
    [DateTime] 
FROM 
    [Sample] 
; 

你也可以考虑WHILE块。

Answer 2

使用此代码：

------------------ INPUT ------------------------ 
declare @start_date datetime = '01/01/2000 14:00' 
declare @loops int = 5 
------------------------------------------------- 

declare @i int = 0 
while (@i < @loops) begin 
    select dateadd(hour, @i * 2, @start_date) 
    set @i = @i + 1 
end 

Answer 3

试试这个没有LOOP

Declare @count int = 5, 
     @incrementer int =2 -- in case if you want to change the incrementer 

SELECT Dateadd(hh, num * @incrementer, dates) 
FROM (SELECT Cast(CONVERT(VARCHAR(20), Dateadd(dd, 1, Getdate()), 111) 
        + ' 9:00 AM' AS DATETIME) AS Dates, 
       num 
     FROM (VALUES(0),(1),(2),(3),(4),(5)) TC (num)) A 
WHERE num <= @count - 1 

• SQL FIDDLE DEMO

Answer 4

Create Table dates 
    (
    datetimefield datetime not null 
    ) 
    go 

Create Procedure FillDateTimeField 
@insertxrows int 
AS 
begin 
Declare @LastDateTimeInserted as datetime 
set @LastDateTimeInserted = (select isnull(max(datetimefield),getdate()) from Dates) 
;WITH norows AS (
    SELECT 1 as num, Dateadd(hour,2,@LastDateTimeInserted) as FirstRecord 
    UNION ALL 
    SELECT num + 1, dateadd(hour,2,firstrecord) FROM 
    norows 
    WHERE num < @insertxrows 
) 
insert into dates 
select firstrecord from norows 
end 

Answer 5

普莱斯e找到下面的示例代码，它包含您需要的逻辑。希望能帮助到你！！

--Create a temp table for sample output 
CREATE TABLE #temp 
( 
CreatedDate datetime 
) 

--Declaring variables 
DECLARE @Count int 
DECLARE @TimeCounter int 
--intializing values 
SET @Count=5 
SET @TimeCounter=0 


WHILE(@Count>0) 
BEGIN 
--SELECT getdate()+1 
insert into #temp(#temp.CreatedDate) Select DATEADD(hour,@TimeCounter,getdate()) 
SET @TimeCounter=@TimeCounter+2 
SET @Count=@Count-1 
END 
--Final values 
SELECT * FROM #temp tmp 
--Dropping table 
DROP TABLE #temp 

Answer 6

这是用数字表格/函数最好解决的那些问题之一。与递归或循环相比，代码少得多，通常对于任何不平凡且更可重用的更快的代码。

你想要的核心代码是

CREATE PROCEDURE usp_PopulateAppointments 
(
    @StartDateTime datetime2(3), 
    @Records  int, 
    @Interval  int = 120  --Time between appointment slots in minutes. Default to 2h if not manually specified. 
) 

INSERT INTO Appointments 
SELECT 
    DATEADD(m, @Interval * Number, @StartDateTime) 
FROM dbo.udfNumbers(0, @Recs) 

我认为在这一个数字函数，它@StartAt和@NumberResults。我在http://sqlblog.com/blogs/adam_machanic/archive/2006/07/12/you-require-a-numbers-table.aspx的评论中使用了从Adam的最终代码中派生出来的一个 - 根据我的经验，它比实际的表更快，并且占用更少的空间。