September 03, 2010

Make a T-SQL Query Sleep for a certain amount of time

At times, in test scenarios, you may want to emulate that a transaction or a T-SQL query takes ‘x’ amount of time. Well that is possible (although not with precision) in SQL Server (2005/2008) using the WAITFOR command.

Here’s an example of delaying query execution till a specified time interval has elapsed – let us say 10 seconds

USE Northwind
WAITFOR DELAY '00:00:10';
SELECT LASTNAME, FIRSTNAME FROM Employees;




OUTPUT

image

As you can see, we used the WAITFOR statement with a DELAY option to delay code execution for 10 seconds.

There are a couple of things you should note about the WAITFOR statement

- WAITFOR does not accept date values, only time values are allowed

- In some scenarios, the delay specified by you may not exactly the same as the delay caused by WAITFOR


About The Author

Suprotim Agarwal, ASP.NET Architecture MVP works as an Architect Consultant and provides consultancy on how to design and develop Web applications.

Suprotim is also the founder and primary contributor to DevCurry, DotNetCurry and SQLServerCurry. He has also written an EBook 51 Recipes using jQuery with ASP.NET Controls.

Follow him on twitter @suprotimagarwal

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