Thread: Extending SQL with a C function

Hi,

how can I write a SQL extention in C, which works with "unusual" data
types?

I've managed to write a c function, which accepts int4 as input parameter
and has got int4 as output parameter.

My problem now is, that I want to use a char(10) as input parameter, since
the input for that function is a colum, which is a char(10) type.
How do I do this?

(In the manuals, it is said, one should create an own data type in C - I've
already done this, called it "char10", but of course, I cannot use this
data type in SQL...)

Thank you very much
  Christoph
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Hi,

I still haven't found it out, so here's my question again:

> how can I write a SQL extention in C, which works with "unusual" data
> types?
>
> I've managed to write a c function, which accepts int4 as input parameter
> and has got int4 as output parameter.
>
> My problem now is, that I want to use a char(10) as input parameter, since
> the input for that function is a colum, which is a char(10) type.
> How do I do this?
>
> (In the manuals, it is said, one should create an own data type in C - I've
> already done this, called it "char10", but of course, I cannot use this
> data type in SQL...)
>
Thank you very much
  Christoph
--
** http://ourworld.compuserve.com/homepages/ChLorenz/ ** ChLorenz@csi.com **
 ** No Spam ! ** No Adverts ! ** No Junk-Mails ! ** No unwanted Mails ! **

At 11:26 +0300 on 2/6/98, Christoph Lorenz wrote:


> > how can I write a SQL extention in C, which works with "unusual" data
> > types?
> >
> > I've managed to write a c function, which accepts int4 as input parameter
> > and has got int4 as output parameter.
> >
> > My problem now is, that I want to use a char(10) as input parameter, since
> > the input for that function is a colum, which is a char(10) type.
> > How do I do this?
> >
> > (In the manuals, it is said, one should create an own data type in C - I've
> > already done this, called it "char10", but of course, I cannot use this
> > data type in SQL...)

char(10) is not, in fact, an "unusual" datatype. It's what postgres calls
"bpchar" (blank-padded char). I think there is an interface for dealing
with bpchar fields, which carry their own maximum length which you have to
decode before using.

Herouth

--
Herouth Maoz, Internet developer.
Open University of Israel - Telem project
http://telem.openu.ac.il/~herutma