December 28, 2007 at 4:58 am
I have been posed a question, and I have a solution that is a little too manual for my liking! Can anyone help me produce a query that will do the following in a single query?
We have a table that stores data of people we come into contact with and I need to produce a summary report for the people in custody in 30 minute intervals from 15:30 06/12/2007 until 10:00 24/12/2007. I can do it using the following query, but changing the EndTime and StartTime to all of the intervals in the above time:
SELECT unit.Surname_Cache AS 'Custody Unit', COUNT(*) AS 'Detainee count'
FROM TBL_GPPCustodyEvent event WITH(NOLOCK)
LEFT JOIN TBL_GPerson unit WITH(NOLOCK) ON event.GPPCAUnit_RId = unit.Id
WHERE event.EndTime > '2007-12-06 15:30'
AND event.StartTime < '2007-12-06 15:30'
GROUP BY event.GPPCAUnit_RId, unit.Surname_Cache
ORDER BY unit.Surname_Cache
Is there a method to complete the report in one query?
Any help will be appreciated.
Regards,
Phil
PS As part of the select it would have to show the date & time being queried so that the report made sense! I.e. 2007-12-06 15:30 etc.
Regards,
Phil
January 2, 2008 at 4:39 am
I'm not sure if anyone is interested, but I have a solution (not the most elegant no doubt). Feel free to post comments - I like to learn better ways of working.
Cheers,
Phil
Solution:
-- CREATE TEMP TABLES TO BUILD DATES
USE TempDB
GO
CREATE TABLE [dbo].[#Hours](
[Hour] [varchar](50) COLLATE Latin1_General_CI_AS NULL
)
INSERT INTO #Hours (Hour)
SELECT '00' UNION ALL
SELECT '01' UNION ALL
SELECT '02' UNION ALL
SELECT '03' UNION ALL
SELECT '04' UNION ALL
SELECT '05' UNION ALL
SELECT '06' UNION ALL
SELECT '07' UNION ALl
SELECT '08' UNION ALL
SELECT '09' UNION ALL
SELECT '10' UNION ALL
SELECT '11' UNION ALL
SELECT '12' UNION ALL
SELECT '13' UNION ALL
SELECT '14' UNION ALL
SELECT '15' UNION ALL
SELECT '16' UNION ALL
SELECT '17' UNION ALL
SELECT '18' UNION ALL
SELECT '19' UNION ALL
SELECT '20' UNION ALL
SELECT '21' UNION ALL
SELECT '22' UNION ALL
SELECT '23'
CREATE TABLE [dbo].[#Mins](
[Min] [varchar](50) COLLATE Latin1_General_CI_AS NULL
)
INSERT INTO #Mins
SELECT '00' UNION ALL
SELECT '30'
CREATE TABLE [dbo].[#Days](
[Day] [varchar](50) COLLATE Latin1_General_CI_AS NULL
)
INSERT INTO #Days
SELECT '06' UNION ALL
SELECT '07' UNION ALl
SELECT '08' UNION ALL
SELECT '09' UNION ALL
SELECT '10' UNION ALL
SELECT '11' UNION ALL
SELECT '12' UNION ALL
SELECT '13' UNION ALL
SELECT '14' UNION ALL
SELECT '15' UNION ALL
SELECT '16' UNION ALL
SELECT '17' UNION ALL
SELECT '18' UNION ALL
SELECT '19' UNION ALL
SELECT '20' UNION ALL
SELECT '21' UNION ALL
SELECT '22' UNION ALL
SELECT '23' UNION ALL
SELECT '24'
-- CREATE TEMP DATE TABLE
CREATE TABLE [dbo].[#DateAndTime] (
[DateAndTime] [datetime]
)
-- POPULATE TEMP TABLE
INSERT INTO #DateAndTime
SELECT CAST('2007-12-' + [Day] + ' ' + [Hour] + ':' + [Min] AS datetime)
FROM #Hours, #Mins, #Days
USE NicheLive
GO
SELECT DateAndTime AS 'Time', unit.Surname_Cache AS 'Custody Unit', COUNT(*) AS 'Detainee count'
FROM TBL_GPPCustodyEvent event WITH(NOLOCK)
LEFT JOIN TBL_GPerson unit WITH(NOLOCK) ON event.GPPCAUnit_RId = unit.Id,
#DateAndTime
WHEREevent.StartTime < DateAndTime
ANDevent.EndTime > DateAndTime
GROUP BY DateAndTime, event.GPPCAUnit_RId, unit.Surname_Cache
ORDER BY DateAndTime, unit.Surname_Cache
-- DROP TEMP TABLES
DROP TABLE #Hours
GO
DROP TABLE #Mins
GO
DROP TABLE #Days
GO
DROP TABLE #DateAndTime
GO
Regards,
Phil
January 2, 2008 at 9:35 am
Your solution looks like the best way to handle that particular problem but I would make 2 changes.
Instead of creating a temporary table each time you run the report I would create a perm table with an indexed datetime field. For a 20 year period it would only hold around 35,000 rows which won't take up very much space and since its indexed will probably speed your query up dramatically over creating a temp table each time.
The only other change I would make is to make either (or both) your > or = or <=. Or consider using a between.
DateAndTime BETWEEN event.EndTime and event.StartTime
Currently if the StartTime or EndTime is exactly 00 or 30 that row will never be counted. It won't happen very often what with milliseconds being counted but even if it happens once it will be a pain to figure out what went wrong.
Kenneth
Kenneth FisherI was once offered a wizards hat but it got in the way of my dunce cap.--------------------------------------------------------------------------------For better, quicker answers on T-SQL questions, click on the following... http://www.sqlservercentral.com/articles/Best+Practices/61537/[/url]For better answers on performance questions, click on the following... http://www.sqlservercentral.com/articles/SQLServerCentral/66909/[/url]Link to my Blog Post --> www.SQLStudies.com[/url]
January 3, 2008 at 1:22 am
Thank you for your feedback, I appreciate all the help I get from this site and I am particularly impressed by (a) the speed in which I have had responses in the past and (b) the impressive amount of knowledge people have with SQL Server and T-SQL.
Regards,
Phil
Regards,
Phil
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