Question

I am trying to create a query to provide me with the turnaround time in minutes of a number of rows of testing data.

A succinct version of the table is:

TestName, StartDateTime, EndDateTime

And I am looking for a query that can give me a output something like:

Distinct TestName 
, StartDate[not time]
, Count(rows) as Total
, Count(rows where datediff(minute, StartDateTime, EndDateTime) <=60) as NonBreach
, Count(rows where datediff(minute, StartDateTime, EndDateTime) >60) as Breach
, Count(rows where datediff(minute, StartDateTime, EndDateTime) >60) / Count(rows) as BreachRate

Is this principle even possible?

Any direction would be greatly appreciated.

Answer 1

You could use something like this:

SELECT  TestName,
        CAST(StartdateTime AS DATE) AS StartDate,
        COUNT(*) AS Total,
        COUNT(CASE WHEN DATEDIFF(MINUTE, StartDateTime, EndDateTime) <= 60 THEN 1 END) AS NonBreach,
        COUNT(CASE WHEN DATEDIFF(MINUTE, StartDateTime, EndDateTime) > 60 THEN 1 END) AS Breach,
        1.0 * COUNT(CASE WHEN DATEDIFF(MINUTE, StartDateTime, EndDateTime) > 60 THEN 1 END) / COUNT(1) AS BreachRate
FROM    YourTable
GROUP BY TestName, CAST(StartdateTime AS DATE)

Although depending on your DBMS you may need to use a different method of removing the time from the date.

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Removing time from date:

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SQL-Server 2008 and later:

SELECT  CAST(CURRENT_TIMESTAMP AS DATE)

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SQL-Server 2005 and Earlier

SELECT  DATEADD(DAY, DATEDIFF(DAY, 0, CURRENT_TIMESTAMP), 0)

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MySQL & SQLite

SELECT  DATE(CURRENT_TIMESTAMP)

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Oracle

SELECT  TRUNC(CURRENT_TIMESTAMP)

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Postgresql

SELECT  CURRENT_TIMESTAMP::DATE

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