Returning a boolean expression in a SELECT clause

[Pep Gómez]

Hi... Im trying to return a boolean expression in a SELECT clause and not
being capable.
It seems strange to me that SQL Server can't do that because it can return
other expressions (arithmetic for example).

What I want to do is return in a column wheter some expression is True or
False. For example, imagine I have a table in which I have a column with the
age of people. I want to return the name of the person and whether this
person is older than 20.
What I would do is somthing like:

SELECT Name, (Age>20) As IsOlder
FROM People

But that doesn't work :-(
Is there any way I can accomplish this? Thank you in advance

Pep
pep@ati.es

[Daniel Reber]

try this:

select
name,
case when Age>20
then 1
else 0
end IsOlder
from People

if you are using ADO, it will interpret 1 as True and 0 as False.

if you want it to come back with "True" or "False" try this

select
name,
case when Age>20
then 'True'
else 'False'
end IsOlder
from People

just be aware that the return value is a string. You will need to convert it
to a boolean at the front end.

Daniel Reber


"Pep Gómez" <pep@ati.es> wrote in message news:3bc55a52@news.devx.com...
> Hi... Im trying to return a boolean expression in a SELECT clause and not
> being capable.
> It seems strange to me that SQL Server can't do that because it can return
> other expressions (arithmetic for example).
>
> What I want to do is return in a column wheter some expression is True or
> False. For example, imagine I have a table in which I have a column with
the
> age of people. I want to return the name of the person and whether this
> person is older than 20.
> What I would do is somthing like:
>
> SELECT Name, (Age>20) As IsOlder
> FROM People
>
> But that doesn't work :-(
> Is there any way I can accomplish this? Thank you in advance
>
> Pep
> pep@ati.es
>
>

[Richard Lalonde]

Try this
Boolean can be interpreted as (Yes, No) or (0, 1, -1)

select employeeID, datediff(yy,birthdate,getdate()) as Age,
case
when datediff(yy,birthdate,getdate()) >= 50 then 'Y'
else 'N'
end as IsOlder
from northwind.dbo.employees

"Pep Gómez" <pep@ati.es> wrote:
>Hi... Im trying to return a boolean expression in a SELECT clause and not
>being capable.
>It seems strange to me that SQL Server can't do that because it can return
>other expressions (arithmetic for example).
>
>What I want to do is return in a column wheter some expression is True or
>False. For example, imagine I have a table in which I have a column with
the
>age of people. I want to return the name of the person and whether this
>person is older than 20.
>What I would do is somthing like:
>
>SELECT Name, (Age>20) As IsOlder
>FROM People
>
>But that doesn't work :-(
>Is there any way I can accomplish this? Thank you in advance
>
>Pep
>pep@ati.es
>
>