Re: OCI - How do I retrieve result columns from a 'SELECT * FROM MYTABLE' statement

From: Who <who_at_who.com>
Date: Sun, 23 Jan 2000 02:42:38 -0800
Message-ID: <xjyi4.3$OK5.53@news.pcnet.com>

Markus, I took a look at your example because I was having some trouble getting this same type of thing working. I had some question on why you allocated so much memory in the following 2 sections of code.

Section 1: This adds more and more memory for each column.

      nRecLen += colinfo[ii].buf_len + ( strlen( colinfo[ii].col_name ) ) + (6+2);

      // allocate that memory for the work buffer
      colinfo[ii].pWork = (char*) malloc( nRecLen + 1 );
      if ( colinfo[ii].pWork == NULL )
      {
         printf( "panic, no memory left\n" );
         exit(1);
      }

Section 2: If you were to add up the top, wouldn't nRecLen have the RecLen for all the columns already?

   nRecLen = ( nCols * nRecLen ) + 1;

//
// alloc memory for the out buffer
//

   pRec = (char*) malloc( nRecLen );
   if ( pRec == NULL )
   {

      printf( "panic, no memory left\n" );
      exit(1);

   }

Maybe I am missing something...

Markus <nobody_at_nowhere.edu> wrote in message news:3886C685.B6717BD2_at_nowhere.edu...

> first you have to find out how many columns the result set has:
> attached file line 521: OCIAttrGet( ..., ..., ..., ...,
> OCI_ATTR_PARAM_COUNT, ... );
>
> second you ask for each coltype:
> attached file line 562+: OCIParamGet(...
>
> have fun
> markus
>
>
> Sebastian Corbay wrote:
> >
> > I use OCI to get rows from a table on Oracle 8.
> > I successfully, connect to the server, prepare the statement, execute
> > this statement, but...
> >
> > I don't know how to get the results.
> >
> > The problem is that I cannot set local variables (with OCIDefineByPos)
> > to retrieve value through an OCIFetch, because I do not
> > know how many columns are returned and the type of these columns.
> > I read the Oracle Call Interface Programmer's Guide, but I did not find
> > anyway how to get information about the results returned.
> >
> > What am I supposed to do?
> >
> > Thank in advance for your help!

Received on Sun Jan 23 2000 - 04:42:38 CST