Sleep Command in T-SQL?

Question

Is there to way write a T-SQL command to just make it sleep for a period of time? I am writing a web service asynchronously and I want to be able to run some tests to see i

Answer 1

WAITFOR DELAY 'HH:MM:SS'

I believe the maximum time this can wait for is 23 hours, 59 minutes and 59 seconds.

Here's a Scalar-valued function to show it's use; the below function will take an integer parameter of seconds, which it then translates into HH:MM:SS and executes it using the EXEC sp_executesql @sqlcode command to query. Below function is for demonstration only, i know it's not fit for purpose really as a scalar-valued function! :-)

    CREATE FUNCTION [dbo].[ufn_DelayFor_MaxTimeIs24Hours]
    (
    @sec int
    )
    RETURNS
    nvarchar(4)
    AS
    BEGIN


    declare @hours int = @sec / 60 / 60
    declare @mins int = (@sec / 60) - (@hours * 60)
    declare @secs int = (@sec - ((@hours * 60) * 60)) - (@mins * 60)


    IF @hours > 23 
    BEGIN
    select @hours = 23
    select @mins = 59
    select @secs = 59
    -- 'maximum wait time is 23 hours, 59 minutes and 59 seconds.'
    END


    declare @sql nvarchar(24) = 'WAITFOR DELAY '+char(39)+cast(@hours as nvarchar(2))+':'+CAST(@mins as nvarchar(2))+':'+CAST(@secs as nvarchar(2))+char(39)


    exec sp_executesql @sql

    return ''
    END

IF you wish to delay longer than 24 hours, I suggest you use a @Days parameter to go for a number of days and wrap the function executable inside a loop... e.g..

    Declare @Days int = 5
    Declare @CurrentDay int = 1

    WHILE @CurrentDay <= @Days
    BEGIN

    --24 hours, function will run for 23 hours, 59 minutes, 59 seconds per run.
    [ufn_DelayFor_MaxTimeIs24Hours] 86400

    SELECT @CurrentDay = @CurrentDay + 1
    END