Case Statement With Bigger than?

Hi

How can i create a case statement with a bigger and smaller than sign in it. I keep on getting an error.

Here is the piece of code i'm working on and simply enough, the idea of what i am trying to accomplish.

Code Snippet

SELECT Weight.Weight,

Height.Height,

(Weight.Weight/(Height.Height*Height.Height)) AS BMI,

CASE BMI

WHEN (BMI < 18) THEN 'Under Weight'

WHEN (BMI < 25) THEN 'Healthy Weight'

END AS 'BMI Grouping'

Any Help will be greatly appreciated

Kind Regards

Carel Greaves

Carel:

It looks to me like you have it correct; the only thing you might want to do is add an additonal line after your WHEN statements -- something like

Code Snippet

ELSE 'Over Weight'

Oh the problem is that you cannot reference this as 'BMI'; you need to write out the long version like:

Code Snippet

SELECT Weight.Weight,

Height.Height,

(Weight.Weight/(Height.Height*Height.Height)) AS BMI,

CASE BMI

WHEN ((Weight.Weight/(Height.Height*Height.Height)) < 18) THEN 'Under Weight'

WHEN ((Weight.Weight/(Height.Height*Height.Height)) < 25) THEN 'Healthy Weight'

END AS 'BMI Grouping'

Transact SQL does not have the ability to alias BMI as in your original statement as (I think) Oracle does.

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The "case" function has two formats. You can not use both at the same time.

case -- BMI

when BMI < 18 then 'Under Weight'

when BMI < 25 then 'Healthy Weight'

else NULL

end as 'BMI Grouping'

AMB

|||

Carel,

Expanding upon Alejandro's response, CASE works like this:

CASE {ItemToTest}

WHEN {Value} THEN [AlternativeValue}

END

or

CASE

WHEN {ItemToTest} equality {Values} THEN {AlternativeValue}

END

The second alternative has quite a bit of flexibility. Each WHEN can test different {ItemToTest}, and

{AlternativeValue} can return a different datatype that {ItemToTest}.

|||

And you are not allowed to use the Column Aliase name as expression of other column in the same select list..

You have to use the following query,

Code Snippet

SELECT Weight.Weight,

Height.Height,

(Weight.Weight/(Height.Height*Height.Height)) AS BMI,

CASE

WHEN ((Weight.Weight/(Height.Height*Height.Height)) < 18) THEN 'Under Weight'

WHEN ((Weight.Weight/(Height.Height*Height.Height)) < 25) THEN 'Healthy Weight'

END AS 'BMI Grouping'

|||Thanks, yet again i find all the answers that i'm looking for

Thanks Guys

Kind Regards

Carel Greaves

|||

You are welcome; it is always a pleasure working with you, Carel.