SQL Server患者普查平均按天和小時

Question

我需要創建患者人口普查報告，顯示給定時間段內每小時和每週每天的平均患者人數。例如，這可以讓我顯示，在過去的6個月中，星期一的急診室平均有4人。我有一個表值函數，將顯示以下患者： VisitID，FromDateTime，ThruDateTime，LocationID。

我能夠使用下面的代碼顯示例如ER中給定日期的患者人數。但它僅限於一天。 （改編自http://www.sqlservercentral.com/Forums/Topic939818-338-1.aspx）。

--Census Count by Date Range-- 
DECLARE @BeginDateParameter DateTime, @EndDateParameter DateTime 
SET @BeginDateParameter = '20160201' 
SET @EndDateParameter = '2016-02-01 23:59:59.000' 
---------------------------------------------------- 
-- Create a temp table to hold the necessary values 
-- plus an extra "x" field to track processing 
---------------------------------------------------- 
IF OBJECT_ID('tempdb..#Temp') IS NOT NULL DROP TABLE #Temp 
CREATE TABLE #Temp (ID INT Identity NOT NULL, VisitID VarChar(100), SourceID VarChar(100), 
    FromDateTime DateTime, ThruDateTime DateTime, x INT) 

---------------------------------------------------- 
-- Populate the temp table with values from the 
-- the actual table in the database 
---------------------------------------------------- 
INSERT INTO #Temp 
SELECT VisitID, FromDateTime, ThruDateTime 
FROM PatientFlowTable(BeginDateParameter,@EndDateParameter) 
WHERE (FromDateTime BETWEEN @BeginDateParameter AND @EndDateParameter +1 
OR ThruDateTime BETWEEN @BeginDateParameter AND @EndDateParameter +1) 
AND LocationID = 'ER' 


-- Given Period is taken as inclusive of given hours in the input (eg. 15:25:30 will be taken as 15:00:00) 
-- frist make sure that the minutes, seconds and milliseconds are removed from input range for clarity 
set @BeginDateParameter = dateadd(hh, datepart(hh,@BeginDateParameter), convert(varchar(12),@BeginDateParameter,112)) 
set @EndDateParameter = dateadd(hh, datepart(hh,@EndDateParameter), convert(varchar(12),@EndDateParameter,112)) 

-- you may create this CTE by other ways (eg. from permanent Tally table)... 
;with dh 
as 
(
select top 24 
    DATEADD(hour,ROW_NUMBER() OVER (ORDER BY [Object_id])-1,convert(varchar(12),@BeginDateParameter,112)) as HoDstart 
    ,DATEADD(hour,ROW_NUMBER() OVER (ORDER BY [Object_id]),convert(varchar(12),@BeginDateParameter,112)) as HoDend 
    ,ROW_NUMBER() OVER (ORDER BY Object_id)-1 as DayHour 
from sys.columns -- or any other (not very big) table which have more than 24 raws, just remamber to change 
       -- [Object_id] in OVER (ORDER BY [Object_id]... to some existing column 
) 
select d.DayHour, count(w.VisitID) as PatientCount 
from dh d 
left join #Temp w 
on w.[FromDateTime] < d.HoDend 
    and w.[ThruDateTime] >= d.HoDstart 
where d.HoDstart between @BeginDateParameter and @EndDateParameter 
group by d.DayHour 
order by d.DayHour 

SELECT VisitID, FromDateTime, ThruDateTime 
FROM PatientFlowTable(BeginDateParameter,@EndDateParameter) 
WHERE (FromDateTime BETWEEN @BeginDateParameter AND @EndDateParameter +1 
OR ThruDateTime BETWEEN @BeginDateParameter AND @EndDateParameter +1) 
AND LocationID = 'ER' 

前3個小時的輸出示例顯示出現在ER中的患者考慮到他們的出發時間。

Hour PatientCount 
0  2 
1  3 
2  3 

Answer 1

對於查詢短時間段，我會創建一個表值函數來生成小時條目。結果表可以加入到您的查詢中。

CREATE FUNCTION [dbo].[f_hours] (@startDateTime DATETIME, 
           @endDateTime DATETIME) 
RETURNS @result TABLE (
    [dateTime] DATETIME PRIMARY KEY 
) 
AS 
BEGIN 
    DECLARE 
    @dateTime DATETIME = @startDateTime, 
    @hours INT  = DATEDIFF(hour, @startDateTime, @endDateTime) 

    WHILE (@dateTime <= @endDateTime) 
    BEGIN 
    INSERT 
     INTO @result 
     VALUES (@dateTime) 

    SET @dateTime = DATEADD(hour, 1, @dateTime) 
    END 

    RETURN 
END 

GO 

功能所需的時間可以通過SET STATISTICS TIME ON輸出。爲了生成超過6000條記錄，需要我的電腦53 ms。

SET STATISTICS TIME ON 

SELECT * 
    FROM [dbo].[f_hours]('2016-02-01', '2016-02-10 16:00') 

SET STATISTICS TIME OFF