Hi, Dan.

Thanks a lot for your help. I have tried your code, and basically it's
like mine. So they return the same results... when retrieving text it
works like it should, but not when it comes to numerical data.

What I forgot to tell you, is that the database is created in Firebird
Workbench that I think use IBO. It might be that Firebird Workbench
(IBO) stores numbers in a special format that creates my problem.

If you have any input on this, I'll be more than happy.

Well, thanks again for your support :)

Henrik


-----Original Message-----
From: nitaligavino <Dan.Crea@...> [mailto:Dan.Crea@...]
Sent: Thursday, January 23, 2003 6:15 PM
To: ib-support@yahoogroups.com
Subject: [ib-support] Re: API: Retrieve/fetch numerical data from
database (like an integer/long)

Hello:

Sorry Henrik, I was unable to follow your code snip-it so I don't
have a suggestion on your specific code. However, I have included
some code that I use to allocate the XSQLDA structure after calling
describe, isc_dsql_describe(.), and before calling isc_dsql_fetch
(.). Maybe this will help you:

Once I have allocated the necessary storage I then pass the XSQLDA to
the isc_dsql_fetch(.) to get the results.


I first call this helper to allocate an XSQLDA structure to hold the
result set:

bool IBRecord::Helper_AllocCS(XSQLDA **pDataObj, AT_CUSHORT usFields)
{
// Don't re-allocate if we have enough space already
if(*pDataObj && (usFields <= (*pDataObj)->sqln))
return(true);

// Allocate control storage in bytes
if(usFields > 0 && (*pDataObj = (XSQLDA *)new char
[XSQLDA_LENGTH(usFields)]))
{
// Fill in the version and size
(*pDataObj)->version = SQLDA_VERSION1;
(*pDataObj)->sqln = usFields; // Number of
elements in sqlvar array

// Clear the sql variants being pointed to so we have
a known state
// Since we have one contiguous buffer we can simply
clear from the start
// of the sqlvar structures through the end
memset((void *)(*pDataObj)->sqlvar, 0, (usFields *
sizeof(XSQLVAR)));
return(true);
}

return(false);
}

After the XSQLDA structure is allocated, a call to this method is
made, I loop through the described result set to properly allocate
the variant storage based on the column's described type and null-
ability:

bool IBRecord::Helper_AllocVS(XSQLDA **pDataObj)
{
if(*pDataObj)
{
// Allocate the needed storage
for(int iAlloc=0;iAlloc < (*pDataObj)->sqld;iAlloc++)
{
// Get a pointer to the variant
XSQLVAR *pSqlVar = &(*pDataObj)->sqlvar
[iAlloc];

// Coerce the type from a varying to a text
switch(pSqlVar->sqltype)
{
// Set the varying to NOT NULL text
case SQL_VARYING:
pSqlVar->sqltype = SQL_TEXT;
break;

// Set the varying to nullable text
case SQL_VARYING + 1:
pSqlVar->sqltype = SQL_TEXT +
1;
break;
};

// Allocate sqllen bytes, if we fail then
return false
if((pSqlVar->sqldata = new char[pSqlVar-

>sqllen]) == 0)

{
// Free anything that might have been
allocated
Helper_FreeVS(pDataObj);
return(false);
}

// See if we need to allocate space for the
null indicator flag
if(pSqlVar->sqltype & 1)
pSqlVar->sqlind = new short;

}

return(true);
}

return(false);
}

Best regards,
Dan
--- In ib-support@yahoogroups.com, "Henrik Sitter"
<henrik.sitter@e...> wrote:

> Hello,
>
> I'm working on and off with the Firebird API, and right now I'm

trying

> to retrieve/fetch data from my test database.
>
> As long as the data is stored as VarChar or char, everything works

like

> it should, but when it's stored as numerical data (like an

integer), the

> database returns just BS.
>
> In the coercing and allocating part of my code I use (I suspect
> something is wrong here):
>
> #define ALIGN(ptr, n) ((ptr + n - 1) & ~(n - 1))
> char *r_buffer, *rec_buffer;
> .
> .
> case SQL_LONG:
> r_buffer = (char *)malloc(sizeof(long)+sizeof(int));
> rec_buffer = (char *)ALIGN((long)r_buffer, (sizeof(long)+sizeof

(int)));

> var->sqldata = (char *)((long)rec_buffer);
> break;
> .
> .
>
> In the fetching part I use (this part works, at least when fetching

char

> and VarChar):
>
> .
> .
> int fetch_stat;
> while ((fetch_stat = isc_dsql_fetch(status_vector, &st1, 1,

my_xsqlda))

> == 0)
> {
> for (i = 0; i < my_xsqlda->sqld; i++)
> {
> // process_column is a function that prints the content of
> my_xsqlda->sqlvar[i] to the console.
> process_column(&(my_xsqlda->sqlvar[i]));
> }
> }
> .
> .
>
> Anybody have a clue?

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