February 12, 2014 at 10:46 pm
I am trying to pass a parameter to my report.
This parameter is a calculated one , so needs to be int for calculation purposes, but I may also have to pass "*" which is a varchar.
My current query has the following.
Select
(Cast(DeviceType as Int)-Cast(DeviceTypezone as Int)= @Device or @Device Is Null or @Device = "*")
Can anyone advice?
February 13, 2014 at 12:35 pm
I don't see how the * value behaves differently from NULL; it seems extraneous. Either a calculated value equals @Device, or there was no numeric @Device value entered.
(Cast(DeviceType as Int)-Cast(DeviceTypezone as Int)= @Device or @Device Is Null or @Device = "*")
The above is functionally no different from
(Cast(DeviceType as Int)-Cast(DeviceTypezone as Int)= @Device or @Device Is Null)
If users insist on passing *, you could maybe try adding something at the start of your query like
IF @Device = '*'
SET @Device = NULL
And just use the shorter form of the select without the (or @Device = "*") clause.
February 17, 2014 at 5:55 pm
You can also just use:
NULLIF(@device, '*') IS NULL
My thought question: Have you ever been told that your query runs too fast?
My advice:
INDEXing a poor-performing query is like putting sugar on cat food. Yeah, it probably tastes better but are you sure you want to eat it?
The path of least resistance can be a slippery slope. Take care that fixing your fixes of fixes doesn't snowball and end up costing you more than fixing the root cause would have in the first place.
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Since random numbers are too important to be left to chance, let's generate some![/url]
Learn to understand recursive CTEs by example.[/url]
[url url=http://www.sqlservercentral.com/articles/St
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