--- In firebird-support@yahoogroups.com, "Martijn Tonies"
<m.tonies@u...> wrote:

> Hi Dixon,
>
> > in the following statement:
> > (SUM(d.SD_TOTAL) - SUM(d.SD_QTY*p.PR_PRICE)- SUM(d.SD_QTY *

(SELECT

> > x.TX_AMTEA FROM PRTAXCODE x
> > WHERE (x.TX_CODE=d.SD_TAXCODE AND x.TX_CAT=p.PR_CAT)))) AS

PRODDIF

> >
> > x.TX_CAT and x.TX_CODE and x.TX_AMTEA may or may not be NULL.
> >
> > If it is null, I would like to return a value of zero for the

last

> > subSelect so that the value of this field would be the

difference of

> > (SUM(d.SD_TOTAL) - SUM(d.SD_QTY*p.PR_PRICE) AS PRODDIF
> >
> > is this possible to convert a NULL to a zero on the fly?
>
> In Firebird 1.5, use COALESCE.
>
> With regards,
>
> Martijn Tonies

Thanks Alan and Martijn. Got it working.

Dixon Epperson