Re: Select Statement

On May 21, 10:18 am, t..._at_panix.com (Dan Blum) wrote:
> ame..._at_iwc.net <ame..._at_iwc.net> wrote:
> > Well, I appreciate everyone's advice. but, that is the way the
> > application is designed. And, changing over 4000 PHP scripts is not
> > an option right now. Eventually things will be re-written, but not
> > now.
> > A user function is the way to go. But, the number of parameters
> > passed is not known. The formula can be simple, A + B, that is 2
> > parameters, or A + B - C, that is 3 parameters, A + B - C / D * F that
> > is 5 parameters......
> > So, I have to write some function that accepts a variable number of
> > parameters, for both the value and the operator. And, this has to be
> > done from an SQL statement.
>
> Create a type, like so:
>
> create type number_array is table of number;
>
> Then create a function to check the numbers:
>
> create function foo(numbers number_array) return number_array...
>
> The function iterates through the set of numbers and replaces the ones
> that are -99999 with 0, unless they are all -99999.
>
> You can call this function from SQL. Of course you will need to figure out
> how to get the values from the returned array and use them in the formula -
> but there's no way around that. The approach I would try is passing the
> formula to the same or a different function as a string with bind variables,
> and getting the values in it that way.
>
> Note that you need to define what happens if D in your last example there is
> -99999 - substituting 0 will not work. If you need to substitute 1 instead that
> will complicate matters.
>
> --
> _______________________________________________________________________
> Dan Blum t..._at_panix.com
> "I wouldn't have believed it myself if I hadn't just made it up."

That sounds feasible. I'll have to read on how to pass the values of the selected data as bind variables:

SELECT a + b, c * d, e + f - g
FROM ....... So, all those values would have to be passed to the function......the result would be returned. I'll need 2 arrays, one for the values and one for the operators. I guess the other option is to pass the entire statement as a string, and parse it, and then open a cursor to be read from.....maybe that would work too. But I'd rather just pass the needed values....... Received on Wed May 21 2008 - 10:47:43 CDT