Tag Archives: Development

Articles on Microsoft SQL Server development

#0410 – SQL Server – Dividing a TimeSpan by an Integer to find average time per execution


I recently encountered an interesting question on the forums the other day. The question was how to determine the average time taken by a single execution of the report provided we know how many times the report ran and the total time taken for all those executions.

The challenge is that the total time taken for all the report executions is a timespan value (datatype TIME in SQL Server). A TIME value cannot be divided by an INTEGER. If we try to do that, we run into an error – an operand clash.

USE [tempdb];
GO
DECLARE @timeSpan TIME = '03:18:20';
DECLARE @numberOfExecutions INT = 99;

SELECT @timeSpan/@numberOfExecutions;
GO
Msg 206, Level 16, State 2, Line 6
Operand type clash: time is incompatible with int

The solution is to realize that a timespan/TIME value is ultimately the number of seconds passed from a given instant. Once the timespan is converted to the appropriate unit (number of seconds), dividing by the number of executions should be quite simple.

Here’s the working example:

USE [tempdb];
GO
DECLARE @timeSpan TIME = '03:18:20';
DECLARE @numberOfExecutions INT = 99;

SELECT @timeSpan AS TotalActiveTime,
       DATEDIFF(SECOND,'1900-01-01 00:00:00.000',CAST(@timeSpan AS DATETIME)) AS TotalExecutionTimeInSeconds,
       DATEDIFF(SECOND,'1900-01-01 00:00:00.000',CAST(@timeSpan AS DATETIME))/(@numberOfExecutions * 1.0) AS TimePerExecution;
GO

/* RESULTS
TotalActiveTime  TotalExecutionTimeInSeconds TimePerExecution   
---------------- --------------------------- -------------------
03:18:20.0000000 11900                       120.20202020202020
*/

I trust this simple thought will help in resolving a business problem someday.

Until we meet next time,

Be courteous. Drive responsibly.

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Collapsed Regions using BEGIN_END

#0409 – SQL Server – Code Blocks – Equivalent of #region…#endregion


I was recently participating in a forum and came across an interesting question. What attracted my attention was that the person was trying to keep their T-SQL code clean and readable (which in itself is a rare sight).

The person was trying to group their T-SQL code into regions. In the world of application development technologies (e.g. C#) we would typically use the #region….#endregion combination. However, it does not work with T-SQL because the hash (#) is used to define temporary tables.

In T-SQL, the basic control-of-flow statements¬† that allow you to group the code are the BEGIN…END keywords. The BEGIN…END keywords can be used to logically group code so that they can be collapsed or expanded as required.

Collapsed Regions using BEGIN_END

Collapsed Regions using BEGIN_END

Expanded Regions using BEGIN_END

Expanded Regions using BEGIN_END

Summarizing,

The BEGIN…END keywords are therefore the functional equivalents of the #region…#endregion statements.

Until we meet next time,

Be courteous. Drive responsibly.