--- In firebird-support@yahoogroups.com, Lucas Franzen <luc@r...>
wrote:

>
>
> Muthu Annamalai schrieb:
> > Need help in my Stored Procedure which is as follows
> >
> > SELECT COALESCE(OPENINGBALANCE,0), COALESCE(CASHIN,0),
> > COALESCE(CASHOUT,0), COALESCE(CLOSINGBALANCE,0)
> > FROM CASHACTIVITY
> > WHERE CASHACTIVITY.TODAY =:SALESDAY
> > INTO :OPENINGBALANCE,:CASHIN,:CASHOUT,:CLOSINGBALANCE;
> >
> > In CashActivity Table, if there is no record for given salesday

then

> > my SP is returning nulls, which I expect to return zero's.
>
> No, you're mixing up NULLS with NOT FOUND.
> If your stored proc doesn't find any matching row it will return

the

> initalized variables (which is NULL).
>
> For example:
>
> I = 1;
> WHILE ( I <= 10 ) DO
> BEGIN
> RETURN_VALUE = 0; /* initializing the variable */
> SELECT VALUE1
> FROM SOMETABLE
> WHERE VALUE2 = :I
> INTO :RETURN_VALUE1
> /* if this WHERE won't match any records, the RETURN_VALUE
> variable will stay untouched, meaning it will hold the last
> value it had in the loop, unless you initialize it (a), since
> no record found doesn't return NULL, it returns simply

nothing */

> SUSPEND;
> I = I + 1;
> END
>
>
> So change your SP to sth. like:
>
> OPENINGBALANCE = 0;
> CASHIN = 0;
> CASHOUT = 0;
> CLOSINGBALANCE = 0;
>
> SELECT COALESCE(OPENINGBALANCE,0), COALESCE(CASHIN,0),
> COALESCE(CASHOUT,0), COALESCE(CLOSINGBALANCE,0)
> FROM CASHACTIVITY
> WHERE CASHACTIVITY.TODAY =:SALESDAY
> INTO :OPENINGBALANCE,:CASHIN,:CASHOUT,:CLOSINGBALANCE;
>
>
> > I could easily handle this situation using if null construct,

the

> > problem is ( recently ) after learning about COALESCE i changed

many

> > of my SP's and now I am scared whether I am using coalesce in

right

> > sense.
>
> Luc.

Thanks Luc,

I got the point.

From my understanding from your post,

If the where condition fails then the server won't even look into SP
and will get out of the SP. The variables will have values as
declared.

Thanks for your time.

Muthu