Yes.
A feature of MySQL is that it returns 1 for true and 0 for false. When you
select ... you can put logic tests and sum up the number of true values. In the
case of "bool_was_connected=0" will have a value of 1 when it is true and then
you sum up the results.
You could also do something like:
SUM( bool_was_connected IS NULL )
SUM( boul_was_connected IS NULL OR boul_was_connected=0 )
and do on. Just put the condition you want to be true and count in the SUM().
b.
[EMAIL PROTECTED] wrote:
> Thankyou kindly Bill. Just to verify, SUM adds up values. My data
> is only 1 or 0. I used SUM as an example, the below query you recommend
> will count all 'rows' which are 0, thus returning a number which
> represents how many 0's were found?
>
> Thankyou for the fast reply,
> Calvin
>
> On Thu, 30 Aug 2001, Adams, Bill TQO wrote:
>
> > SELECT SUM( bool_was_connected=1 ) AS was_connected,
> > SUM( bool_was_connected=0 ) AS was_not_connected, etc...
> >
> >
> > b.
> >
> >
> > [EMAIL PROTECTED] wrote:
> >
> > > Evening Gurus,
> > >
> > > I have a small problem that I've beaten to death the past 2 days. I am
> > > trying to get the value of a row, and update another table accordingly.
> > > The data within the row is either a 1 or 0. My issue is in trying to
> > > increment a count for both 1's and 0's.
> > >
> > > In other words, I want to SUM up all the 1's and update a table with
> > > this sum. I also want to sum up all the 0's and add this total count to
> > > the table as well. This can be accomplished in a long query, or in
> > > through a language..what I am trying to accomplish is to get the total sum
> > > of each value without using a WHERE clause. Something akin to:
> > >
> > > SELECT ...
> > > SUM(bool_was_connected),
> > > COUNTNULL(bool_was_connected),
> > > etc...
> > >
> > > the SUM will sum up all non-null values. The COUNTNULL would sum up all
> > > rows which have a value of 0.
> > >
> > > Does anyone have a UDF for this function? I currently don't have room on
> > > my laptop to download the mysql source code in order to write this up. (
> > > Also have not written a udf for mysql up to this point either)
> > >
> >
--
Bill Adams
TriQuint Semiconductor
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